Since Reborn's arrival, Tsuna begins to meet new and strange people. One of those people is Hayato Gokudera, a Mafia member who wants to kill Tsuna in order to become the Vongola boss. Meanwhile, Tsuna is forced to help the volleyball team, including his friend Takeshi Yamamoto, due to his show of strength in the previous episode.
With the reveal that their foe wasn't the real Mukuro, everyone breaks into the Kokuyo Middle School building to face the true mastermind. With no Dying Will, Gokudera having to fend off both Chikusa and Ken, and everyone else unconscious, all hope looks lost, but one of Mukuro's captives my prove to be the ace in the hole.
After the defeat of Mukuro, life goes on normally and Tsuna and his friends all move up a grade at school. However, none of them are in the same class, so Reborn offers them a challenge to catch him, with the prize being a change of the roster. Later, they celebrate at a sushi restaurant owned by Yamamoto's father only to find they do not have enough money to pay for their food and have to work off their debt.
Kyoko's friend Hana is infatuated with Future Lambo and blackmails Tsuna into letting her meet him by threatening to tell Kyoko that Haru is his girlfriend. When Lambo uses the Ten-Year Bazooka, however, something malfunctions and creates a teen Lambo with young Lambo's mind, and to make matters worse, this Lambo escapes from the house.
At Mafia Island, Tsuna fails to prove his identity as the Vongola Family's 10th boss, and is transported to the back of the island where he is given a new chance to prove himself. There, he meets another Arcobaleno, Colonello. Colonello and Reborn put Tsuna through tough training. Meanwhile, another Arcobaleno invades the island with an army.
Tsuna has to swim 15m in school, but being unable to swim, he is trained by Yamamoto, Gokudera and Haru in the public pool. Everyone has his own method, and they decide to compete to see who can get Tsuna to swim the furthest. Reborn interferes this time with a Vongola dolphin that has a dangerous complexion.
To pay off the damage caused in the previous episode, Tsuna works as a lifeguard with Ryohei, only for them and the other boys to be challenged to a swimming race by older lifeguards. Later, Tsuna and his friends run a stand during a summer festival to continue to pay off their debt, only to have run ins with Hibari, and a group of thieves.
Dino manages to fend off the swordsman, Squalo, and explains the situation: a subgroup of the Vongola Family called The Varia is after the Vongola Rings which are held by the leading members of the family, which he then proceeds to give to Tsuna and six other people. They have ten days to train in order to become strong enough to fight off The Varia. Meanwhile, Tsuna's father returns.
Tsuna and the other six members chosen to hold one of the 7 half rings, all start to train, in preparation to face The Varia. Some even get them selves their own home tutors. Meanwhile Tsuna is told that besides him the First Vongola also used gloves, and he will soon find out who the two others with the ring are.
Lambo's fight versus Leviathan of Varia. As a 5 year old and a 15 year old, he stands no chance to the "Levi Volta" attack of Levi. However, when the 15 year old Lambo used the 10 year bazooka, Lambo from 20 years later appears. The 25 year old defeats Leviathan with relative ease using his "Electricco reverse" and "Electrico Cornuta" techniques, but the 5-minute limit of the 10 Year Bazooka ended, and Lambo reverted to his 5 year old form.
Gokudera fights a losing battle to Belphegor. Belphegor's attacks were somehow going right to him without much effort on Bel's part. However, Gokudera figures out the secret to his trick, and unveils his new tecnhique: Rocket Bombs. However, once Gokudera finally strikes Belphegor, he starts to act funny.
After Belphegor reveals his true nature, Gokudera lures Belphegor into the library for a final stand. After a brief struggle between the two, Gokudera won, but as the time limit for the match expired, it became a struggle match for the two. Not wanting to lose his friend, Tsuna persuaded Gokudera to abanadon the ring.
Gokudera's match concludes and the next battle is announced: the battle for the Ring of Rain between Yamamoto and Squalo. Hibari causes a commotion at the school as the battles have caused major damage to the grounds. Dino reveals that Squalo once defeated the Swords Emperor of the old Varia and that Yamamoto's Shigure Souen Style is useless against him. Yamamoto receives a shinai from his father that transforms into a katana only when using the Shigure Souen Style.
Having crushed the Shigure Souen Style before, Squalo becomes confident once more. Yamamoto manages to hurt him with the 8th Form: Pelting Rain, after Squalo revealed he had encountered a different 8th Form. Yamamoto reveals his newly created 9th Form as Squalo bares his fangs. The Shark and Rain collide on this exciting conclusion.
On Tsuna's side of the world, he is curious to know who is the Guardian of the Mist only to faint at the sight of Chikusa and Ken. At the Vongola Compound in Italy, an attempted recon mission is enacted by Iemitsu to find out what happened to Vongola the 9th. When Tsuna regains consciousness, he and his 'family' find out who is really the Guardian of the Mist.
Having found out that Chrome Dokuro is the Vongola's representative of Guardian of the Mist, Tsuna acknowledges her as a part of the family and allows her to take part in the duel. After many exerted attempts to attack 'Marmon' (now known as Viper of the indigo pacifer), Chrome eventually loses to the illusions. However, the battle does not end and an unexpected person comes in to assist in the battle.
The unexpected person, turned from Chrome, turns out to be Rokudo Mukuro. A series of chaotic illusions battle starts. During the fight, Tsuna experiences flashbacks of Mukuro on how he sacrificed himself for Ken and Chikusa to escape. Rokudo Mukuro ends up being the winner, almost killing Marmon, who escaped with his reserved power from the battle field. Rokudo Mukuro fainted after the battle, turning himself back to Chrome.
Everyone in Tsuna's family is worried about the outcome of the Cloud battle. If it's Hibari that's fighting, then they should have a one-hit K.O. no-worry win. However, when it seems that the daunting Gola Mosca is more than he appears to be, even Tsuna, who's still training to complete his Zero-Point, gets very worried.
After the Cloud ring conflict, Xanxus tries retrieve Gola Mosca. After Hibari halts his attempt at retrieval, Mosca goes on a rampage, shooting wildly at everyone friend and foe. Back at the 9th's house it is revealed that the 9th living there is in fact a fake. Tsuna comes to the rescue of his friends and holds off Mosca at which time Mosca attacks Tsuna only.
Tsuna opens Gola Mosca to find the body of the 9th who was its power supply. Xanxus is revealed to have been behind a coup attempt. It is revealed that Tsuna has met the 9th before and that he was the true choice for the position of the 10th Vongola Boss. After which the Sky Match is announced for the next night. Xanxus gives the sky ring to Tsuna before he leaves. The 9th is taken for medical attention and everyone returns home. Tsuna returns to school the next day where he receives an amulet from Kyoko.
All the Guardians have been injected with a poison and rendered unmovable. Hibari, however, manages to help himself and on the way saves Gokudera. On Xanxas' side, Bel and Levi have also been freed. Gokudera rushes to save a helpless Lambo from Levi. Meanwhile, the Sky battle has begun to heat up. Who will get all the rings first?
Tsuna prepares to use the fruit of his hard training: the Zero Point Breakthrough. Xanxas, however, recognises this attack and proceeds in a hectic beatdown. Reborn reveals that maybe using to attack won't beat Xanxas anyway. Is Tsuna going to be okay? Meanwhile, Hibari has saved Yamamoto and Gokudera freed Ryohei. Tsuna's family are all saved but Chrome is...
Xanxas is firing relentlessly leaving no time for Tsuna to execute his attack. But Tsuna is getting...stronger with each hit he takes? What is the Zero Point Breakthrough Revised? Dino arrives at the battle with an unexpected guest and Chrome is being held hostage by Marmon and Bel. What will Gokudera and Yamamoto do?
Dino's unsuspected guest is revealed to be Squalo, who Dino saved instead of Yamamoto and brings to see the sky match. Yamamoto along with Gokudera propose a trade between Mammon and Bel, which turns out to be a well played trick but is countered by Mammon's illusions which binds both Yamamoto and Gokudera, Gokudera of which drops the remaining rings. Tsuna and Xanxus have a struggle where Xanxus powers up, which seems to turn the tide of the battle. Tsuna and Xanxus then charge at each other which results in a huge explosion. After the smoke clears, Tsuna's customized version of the Zero Point Breakthrough (Tsuna adds the word custom on the end of breakthrough to make it his own version). The Zero Point Breakthrough Custom froze Xanxus's hand. Revealing the opposite of the Dying Will Flame.
As the fight continues, Xanxus tries to break the ice and release his flames. However, Tsuna prevents him and begins to freeze Xanxus' entire body. As Xanxus becomes frozen, he reveals that this scenario is similar to when the 9th Vongola froze him. Squalo finally reveals the whole story of what happened 8 years ago during the "Crib Incident" and how the Varia attacked Vongola headquarters but failed due to the freezing of Xanxus. Meanwhile, Ryohei is shown freeing Gokudera, Yamamoto and Chrome from Mammon and Bel's trap. However, Mammon was able to get all the guardian rings and is seen at the end hovering over the frozen Xanxus saying that all the rings will reawaken Xanxus.
After the fight, Xanxus is released with the power of the 7 rings which he was originally released by from the 9th. There is a short flashback of his life, and a secret is revealed: Xanxus is not actually the 9th's blood son, and so, the rings rejected him. At the end of this, an elite group of Varia arrives.
Reborn is hit by Lambo's ten year bazooka and sent to the future. The strange thing is nobody came in his place. Thus Tsunayoshi Sawada tries to make Adult Lambo appear by taking Lambo's bazooka and firing it at him in order to explain what had happened, but results Tsuna to be accidentally shot in the process. He then appears in the world ten years in the future. Hayato Gokudera also appears and soon realise they are not being sent back after the usual time limit. They are then attacked by Lal Milch who is later revealed to be an ally.
Tsuna, Gokudera and Yamamoto goes out of the hideout and to the outside. They try to find Kyoya Hibari but run into Lambo and I-pin protecting Haru Miura and Kyoko from two Millefiore Family members from Blackspell. Just as Future Takeshi Yamamoto is about to defeat them, a cloud of purple smoke appears and the past forms of Takeshi Yamamoto, Lambo, I-pin, Haru, and Kyoko appear.
Yamamoto is knocked unconscious by the Millefiore members while trying to protect everyone. Gokudera uses his ring and opens his box weapon to reveal a cannon. He defeats one of the Millefiore members. While protecting Kyoko, Tsuna manages to defeat the second Millefiore member by using his Zero Point Break Through technique.
While recovering from his injuries, Tsuna learns the only way to return to the past is to gather the guardians, defeat Byakuran and eliminate the man with the glasses, Shoichi Irie. Lal-Mirch teaches Tsuna, Yamamto, and Gokudera about the rings and boxes; The rings are revealed to emit a flame depending on the element of the user and boxes contain weapons or animals enchanted by those flames. Lal Mirch asks Tsuna to open a box of an unknown element as the sky flame is able to open boxes of all elements.
When the battle is over, Hibari shows Tsuna and the others the entrance to his base which is also connected to the Vongola base. Once everyone returns to the Vongola secret base, Bianchi and Fuuta arrive to give new information on the Millefiore Family. They reveal the location of the Millefiore base on Japan which is under the Nanimori Station underground Shopping Mall. They decide they must train before beginning their attack on the Millefiore.
When I-Pin becomes sick, Kyoko and Haru decide that Haru should bring her to a doctor. Haru manages to sneak away from the Millefiore and visit a doctor. Haru is later noticed by one of the Millefiore members. Bianchi arrives to try and assist Haru but they both become cornered by the Millefiore member and his box weapon of bees. Tsuna later arrives and defeats the Millefiore member by using the Zero Point Breakthrough.
Lambo sneaks out of the base when Fuuta goes out to fix a loose cable. Lambo is captured by a Millefiore member who demands the location of the Vongola base. Lambo uses him to his advantage in order to get some candy. After learning of the kidnapping, Tsuna and Fuuta follow a trail of Lambo's candy and find the Millifiore member with Lambo. As Tsuna gains the upper hand in combat, the Millifiore decides to threaten Tsuna with Lambo's life. Afterwards, Hibari, annoyed by the disturbance in Nanimori, easily defeats the Millefiore member
Tsuna's training with Hibari begins. During their battle, Tsuna is trapped enclosed by Hibari's hedgehog box weapon. Hibari reveals Tsuna will die from lack of oxygen if he does not escape. Tsuna, reaching his limit, prepares one final attempt to burn through the hedgehog. He burns a small portion and realizes that small portion is where the Vongola ring was. He realizes his X-Gloves flames must be equal to the Vongola ring's flames to break through. Tsuna collapses from the lack of oxygen. Just then, Tsuna's Vongola ring emits images to Tsuna's head and reveals the past crimes of the Vongola.
Yamamoto and Gokudera begin their training. Whilst Tsuna is in the spike ball, he has a visions of all the Vongola Bosses and their past wrong doings. The bosses demand Tsuna to accept the history of the Vongola but Tsuna refuses. The first Vongola Boss, Vongola Primo, accepts Tsuna as the sucessor to the Vongola. Tsuna then escapes with the help of his upgraded X-Gloves which now emit the sky flames. Continuing their battle, Tsuna grabs one of Hibari's hedgehog box weapon and releases it on Hibari. Meanwhile, Chrome is shown to be inside an abandoned building.
Hibari decides to let Tsuna live, wanting to fight Tsuna when he is finished training. The history of boxes is explained thoroughly by Hibari. Whilst explaining, Bianchi is also explaining everything she knows to Gokudera. It is said that the boxes were made because of coincidence and sold at extremely low prices. There are more than three hundred designs. Meanwhile, Byakuran reveals the 7³ plan; the 7 Mare Family Rings, the 7 Arcobaleno's Pacifiers and the 7 Vongola Family Rings that will give them the ultimate power. Squad 8 is sent to investigate deaths in Japan.
In this episode, Tsuna and Yamamoto learn about Gokudera's past. It is revealed that Hayato is an illegitimate child, born of Bianchi's father, the head of their mafia family, and a famous pianist. It is revealed that she died in a car crash when Hayato is still young. Hayato doesn't find out that she was his mother until years after the crash, but when he finds out, he runs away from home. After learning Hayato's history Glo encounters the past Chrome.
With no escape routes available, and Mukuro Rokudo being in a weakened state, Mukuro explains to Chrome Dukuro that it is up to her to win the fight. Drawing power from both her trust in Mukuro and the Vongola Ring, Chrome's illusions become far more effective, to where even Glo can't tell whether or not they are real. The fight soon concludes in a victory for Chrome, and the future Ryohei is introduced at the very end of the episode.
Chrome is brought back back by Ryohei to the Vongola Hideout, and delivers the message the thesurviving Vongola family members—including the Varia—along with several Alliance families, are planning to attack the Millefiore family in just five days. With the 7 Guardians finally reassembled, it is up to Tsuna to decide whether or not they will participate in the attack.
Due to the Dellinger Phenomenon, the sun has interfered with all signals and has caused technical difficulties worldwide. Because of this, the defenses within the hideout are turned off and the setting becomes dangerous. Reborn explains a little about the Negative Tre ne Sette rays and how the Arcobaleno are affected, and he fears for Lal's life because she is a defective Arcobaleno. She seems to be affected more than Reborn. Meanwhile, Lambo and I-Pin have gotten themselves stuck inside the second power supply room and become blocked in when the backup defenses are turned on. Lambo has destroyed part of the control and the room suddenly becomes dangerously overheated. Finally, it takes Tsuna in his Dying-Will Mode to open the doors and release the children.
As Tsuna trains thoroughly for the raid in five days, Lal Milch is experiencing problems due to the Negative Seven Rays, so she excuses Tsuna to check on Yamamoto and Gokudera. It seems that Yamamoto needs more training, and Gokudera has flaked off from his training. Meanwhile, in Millefiore HQ, Byakuran has found out that Leonardo Lippi is an impostor whose real name is Guido Greco, a man who murdered 15 men and escaped from prison a year ago, similar to that of Mukuro. Byakuran finally reveals that Guido is also Mukuro, and they engage in a battle. Meanwhile, Tsuna finds out Lal's condition and starts to worry, but Lal Milch lectures him on 'choosing the right hell.'
Tsuna apologizes to Haru and Lambo and thanks to them, figures out that behind power, is support. Tsuna tries to release a "hard flame" with "soft flame" supporting him, but fails because he can not find the balance. While unconscious after blasting into a wall, Tsuna and Chrome are sent dreams by Rokudo Mokuro of a strange white "box".Gokudera has finally mastered the Systema C.A.I. and finding a small cat in one of the boxes.
Byakuran calls Irie and tells him that Mukuro has been defeated and that he was found to be transmitting data, possibly to the Vongola Tenth. Byakuran tells Irie that he is the most important person in that base and must escape if they invade the base. Irie for some hidden reason, can't leave. Irie calls all the Milliefore Japan members in the base and tells them he shall leading the base now. The members are outraged and prepare to attack Irie until a swordsman by the name of Genkishi tells them anyone who opposes master Irie will be killed. Irie becomes the boss of the base. Afterwards the Vongola have received the data transmitted by Mukuro. In it was the picture of the white box Tsuna saw in his dreams. Training is resumed and Reborn gives Yamamoto a box about the sword emperor.
Yamamoto and Gokudera have finished their training. Meanwhile, Tsuna loses his charm made by Kyoko. Later, he bumps into her and she gives him it back, then the first black spell battle is recapped. Also, Hibari reveals that the Millefiore battle simulation reveals a 0.0024% chance of success for Vongola. Thanks to Glo Xinia, Millefiore now knows where the Vongola Base is.
Tsuna and the others prepare for their attack the next day. They've been given Marmon covers on their rings which will hide them, dying will resistant clothing, and a communication system. Meanwhile the Millefiore digs their way underground and ends up at where the transmitter was. It turns out Hibari noticed the transmitter and carried it there to lure the Millefiore members away from the base.
Hibari starts knocking the Millefiore members unconscious one by one. The place he lured them to is revealed to be meant for attacks like this. The Vongola find out that one of the shopping malls ducts lead to the Millefiore base. They enter the ducts only to trigger a trap where lasers prepare to fire on them.
GingerBread reveals that Colonnello died by saving Viper who then killed himself out of hopelessness. Lal Mirch remembers back to the past before she becomes an incomplete Acrobaleno because Colonnello took her place. She had a blue incomplete pacifier which she promised not to use so she would become human again. In the present time, Lal Mirch uses her pacifier and defeats GingerBread. It was revealed GingerBread was a doll and explodes, injuring Lal Mirch. Just then the alarm goes off informing Millefiore of their presence.
Tsuna escapes from the grasp of the Moscas and continues his battle. He defeats them the minions but the man named Spanner who pilots the King Mosca remains. Tsuna prepares to give up the fight but Reborn tells him he should use the X Burner in the air. Tsuna defeats the King Mosca but loses consciousness in the process. Spanner leaves the Mosca and prepares to kill Tsuna.
Tsuna's family becomes worried at the amount of time that Tsuna is gone while they continue searching the base. While crawling through an air duct, they run into Baishana and Nigella fighting. Nigella is then beaten by Baishana box weapon, a snake covered in storm flames. Ryohei decides to fight in place of Yamamto and Gokudera and summons his box weapon Kangayuu, a Kangaroo. Back at Tsuna's scene of the battle, Tsuna and Spanner are no where to be found.
The base is moved by Irie Shouichi and Ryohei and Gokudera are separated from Yamamoto and Lal Mirch. Ryohei and Gokudera then run into a white spell Millefiore member who uses his box animal of a slime monster to attack them. Gokudera is trapped inside but is then freed by Uri. He then destroys the box animal. Meanwhile Yamamoto with Lal Mirch wanders into a room and is surprised by what he sees.
Yamamoto ends up in a room full of pipes. There he meets a white-spell Millefiore member who uses a boomerang with the storm flame to attack him. Yamamoto realizes that he could not predict where the attacks are coming from because he is actually fighting twins. Yamamoto defeats them. Irie Shouichi moves the base again and Gokudera and Ryohei run into Gamma.
Ryohei ties up Gokudera with a box weapon to make the battle fair against Gamma. Tsuna meanwhile attempts to escape from Spanner but Reborn who is able to get in contact with him after the base moves closer to the surface, tells him he needs to master the X-Burner or he can not defeat Millefiore. Ryohei is severely injured by Gamma. Hibari continues his way in the subway, surrounded by Milliefiore members once again.
Gokudera talks about his Sistema C.A.I. and explains how he discovered its use. Hibari continues his way into the subway and uses his box weapon to trap the Millefiore members on the other side. Spanner explains to Tsuna that he will create contact lenses so Tsuna would be able to measure his flame power on his gloves and help him balance his X-burner.
It is revealed the Sun flames from Ryohei's box animal was used by Uri to transform. Uri manages to hold back Gamma's box animals while Gokudera deals with Gamma. Meanwhile, Gamma remembers when his family was separate from the Millefiore. In his memory, the boss just died, and her daughter Yuni is the heir.
In Gamma's memory, after a failed bargaining with the Millefiore Family, Genkishi returns with injuries to the Giglio Nero family. Yuni decides to meet with Byakuran to prevent anymore of her subordinates being hurt. After meeting with him privately, Yuni returns emotionless and a loyal servant to Byakuran. Gamma mentions how Genkishi was the biggest traitor to the Giglio Nero Family and how he wants to defeat Byakuran.
Tsuna needs to be placed in battle so the contacts can be adjusted for the X-burner. Tsuna puts on gears that puts him in a virtual space to fight Moscas; he could die if he dies in that space. Later, Irie Shouichi moves the base again and places a virus in the virtual space and Tsuna must defeat it.
Tsuna's contacts are completed and Tsuna waits for the contacts to adjust. Iris and Gingerbread investigate Spanner and suspect him of haboring Tsuna. Yamamoto ends up in a room of water and faces the strongest soldier of the Millefiore, Genkishi. Genkishi reveals that he faked his defeat against Squalo for the purpose of Milliefiore. Back at the Vongola base, Kyoko and Haru are trying to find the missing Chrome, Lambo, and I-pin.
Yamamoto and Genkishi continue to battle, until Yamamoto's sword appears cracked. He then remembers in the video Squalo sent him of Genkishi, that he mentioned mist illusions have gotten to the point it can trick everyone in the surrounding area and even cameras. Meanwhile, Gingerbread and Iris continue searching for Spanner. Yamamoto realizes that Genkishi created the illusion of his sword being cracked and continues their battle.
Gokudera and Gamma finish the battle destroying the battlefield. Meanwhile, Reborn and Tsuna figure out that the circle machine was created by Irie Shouichi for time travel causing them all to be stuck in the future. Iris arrives finding Spanner's hiding place. Genkishi about to deal the final blow to the unconscienced Yamamoto, but is intervened by the arrival of Hibari.
Tsuna defeats Iris and Gingerbread with his X-Burner while destroying three rooms in the process. Meanwhile, Genkishi was about to kill Hibari when the others manage to arrive to Hibari's location and save him. Hibari mentions he's learned how to use the ring from Dino in the past and ignites it. He then uses the flame to release his hedgehog box weapon.
When Hibari starts to open the hedgehog box weapon, the hedgehog starts to act drunk from the flame from the amount of Dying Will Flame given to it. After accidentally poking Hibari's hand, the hedgehog becomes mentally shocked and goes out of control. It rapidly starts to grow, endangering all those around it. Meanwhile, Tsuna is heading towards the others when a plant box weapon blocks his path. He quickly defeats it.
Tsuna flies through Merone Base with a mission and that mission is to find Shoichi Irie and the white, round device in his laboratory. Irie tries to interfere with Tsuna's movements by moving Merone Base's blocks. With Spanner behind him, Tsuna cannot shake off a homing missile, but he is able to fend it off with chaff and flame shots that Spanner modified. He is later intercepted by the Phantom Knight, Genkishi.
Genkishi engages Tsuna in a battle using his hell ring, an armour and a special sword. Tsuna is at a disadvantage as he does not have much energy left due to firing the X Burner few times before. However, Genkishi wavers when Tsuna's resolute eyes reminds him of Yuni. Tsuna then sets up a plan to absorb Genkishi's flames, and he regains his energy. Tsuna gains the upperhand and manages to overpower Genkishi.
Genkishi recalls a certain memory of when he had been ordered by Byakuran to annihilate the Giglio Nero Family but was too intimidated by Yuni's eyes to do so. Genkishi tries to gain even more power from the ring in order to make up for his blunder and transforms into a skeletal figure. However, Tsuna sees through his scheming plots and prepares to fire a full powered X Burner.
Tsuna unleashes a full powered X-Burner and defeats Genkishi. In the wreckage, Tsuna finds Irie Shouichi's white round machine. Irie appears and reveals he's holding all of Tsuna's friend's hostage in a tank. Irie reveals the white round machine holds the older Tsuna and the others. Irie reveals he sent them to the future in order to obtain the Vongola Rings. He demands Tsuna to hand over his Sky Ring or his friends will be killed. The Cervello counts down the time limit for Tsuna to make his decision.
Shouichi tranquilizes the Cervello before they could kill Tsuna's friends. He reveals he is on the Vongola's side, and that all the events that have occurred was a plan devised by Shouichi along with future Tsuna and future Hibari in order to train their past selves to defeat Byakuran. Shouichi reveals that the next step of the plan will depend on the Millefiore base invasion in Italy, which is led by the Varia.
The Varia split up into three groups, Squalo, Lussuria with Levi, and Bel with the new illusionist member of Varia named Flan. Squalo meanwhile finds out Xanxus is displeased with his meal and sends injured soldiers to him. He meets some Milliefiore members and defeats them with his Shark box weapon named Grande Pioggia. Bel and Flan run into Milliefiore members and Bel easily disposes of them with his with his box weapon Storm Mink. Just then, Bel's butler from his childhood, Olgelt, reveals that Bel's older twin brother, Sil is alive. Sil then appears on a flying throne.
Sil is revealed to be one of the Six Funeral Wreaths. Bel, Flan, Olgelt, and Sil release their box weapons for battle. Sil's box weapon is revealed to be a Storm Bats with the ability to fire invisible sonar waves enchanted with storm flames; The storm flames when in contact with something causes an explosion. Bel and Flan are defeated. Olgelt sends his Rain Elephant and destroys the castle the Varia invaded. In the remains of the castle, an unharmed Xanxus on his throne is seen drinking wine.
The corpse of Bel and Flan are revealed to be illusions of Flan, who wanted to see whether Sil or Xanxus is stronger. Olgelt sends his Rain Elephant after Xanxus but they become petrified in mid-flight. Xanxus' Sky Lion box weapon, Besta, is revealed to be the one petrifying the Elephant. Sil attacks Xanxus with his storm bats causing heavy damage to him. Xanxus unmoving from his throne becomes enraged and reveals Besta is actually a Sky-Storm Liger, an offspring from a Sky lion with a Storm tiger.
Xanxus returns Besta to his box, warning Sil that when he releases Besta, he will be finished. Xanxus demands Sil to call Byakuran. Sil refuses and attacks Xanxus with his Storm Bats. Xanxus releases Besta and kills Sil. Tsuna and the others receive news that the battle in Italy was successful. At that moment, Ryohei from ten years ago arrives from the past. Shouichi opens up the white capsule containing the ten years later version of Tsuna and his Guardians and gives Tsuna the Vongola Box from his future self.
Filler Arc: Shoichi Irie tells Tsuna that in order to open the Vongola Box, the Seven Arcobaleno Seals are needed. In order to obtain the seals, Tsuna needs to overcome the Arcobaleno trials. To do so, Irie will momentarily send everyone who came from 10 years ago back home. Chrome Dokuro asks Irie on Mukuro Rokudo's status and Irie reveals that his death was not confirmed. Tsuna and the others return to the Vongola base where they are reunited with everyone else. At the base, Ryohei Sasagawa is filled in on the events that have occurred and Tsuna thinks how he should tell Kyoko and Haru about this and whether they could return to the peaceful days again.
Back in the past, the Arcobaleno are heading to Namimori to present Tsuna with their trials. Meanwhile, in the future, Irie is giving Tsuna and his friends instructions on how to return to the past. The Arcobaleno Trials are a week long. If they don't get all seven seals during that time, they will lose all means to oppose Byakuran. With a newfound determination, Tsuna and his friends return to the Namimori of the past using Irie's device. Tsuna and his friends are thrilled to see a peaceful Namimori. Reborn, previously silent, finally announces the start of the Arcobaleno Trials…
One day has passed since Tsuna and his friends had returned to the past and they still have yet to receive a trial. Reborn says he doesn't know what order the Arcobaleno will appear. Tsuna suggests they should go to school and do as they would usually do. However, during recess they are suddenly attacked on the roof! It is a baby with goggles. It’s Lal Mirch. Lal says that she is the observer to the Arcobaleno Trials. Their first opponent is Colonnello, who has a blue pacifier. Colonnello begins Tsuna and Gokudera's trial to test their combat abilities--!
Colonnello shows off his overwhelming strength. It is a tough fight even for Tsuna and his friends who had gotten stronger through training and fighting in the future. Colonello repeatedly strikes with his powerful punches, kicks, and his killer “Maximum Burst”! Barely able to catch his breath dodging the attacks, Tsuna can’t use his X Burner. However, Gokudera’s cleverness allows them a little bit of time to fire up the X Burner. Tsuna’s X Burner and Colonello’s Maximum Burst are used at the same time—which one will ultimately win….!?
Concern for Chrome brings Tsuna to Kokuyo Health Land. Hibari and Mukuro suddenly show up. The longstanding grudge between the two comes to a boil as soon as their eyes meet and they begin to fight! Tsuna can’t figure out what to do. It seems this unlikely situation was created by Skull, the Arcobaleno with the purple pacifier. At this rate, Hibari and Mukuro will continue to fight until one of them falls. Tsuna becomes panicked when Lal tells him that his trial has begun. On one side, there's Skull's trial and on the other side, Hibari and Mukuro are in fierce combat. Furthermore, Ken and Chikusa show up after noticing the chaos. It's mayhem!
A fog-draped morning, Tsuna is called out to Nami Junior High (?) by a mysterious phone call. On the way there, he runs into Yamamoto, Ryohei, and Gokudera. It turns out that Gokudera had come looking for Tsuna, but Yamamoto and Ryohei had been called out by the same kind of mysterious phone call. Is this one of the Arcobaleno’s tests…? They await suspiciously, and before them, Mammon—or Viper—of the Arcobaleno appears. Mammon says he has taken Kyoko hostage. Regardless of Tsuna and the others’ distraught faces, Mammom coldly kicks off a new mystery-solving game.
Tsuna receives a letter. Inside the letter, there is a photo of someone wearing sunglasses and a note that reads “Try and catch me.” I-Pin sees the photo and is in shock. Reborn says that the person in the photo is I-Pin’s master, Fon, the holder of the red pacifier of the Arcobaleno. I-Pin wants to help Tsuna, but cannot help but is clearly hesitant to capture someone to whom he pledged his loyalty. Perceiving that I-Pin felt that way, Tsuna takes off by himself for the test. The test with Fon is a game of tag. Will Tsuna be able to catch the swift Bushido master?
There are three remaining Arcobaleno tests, one of which is the sky Arcobaleno. Tsuna resembles the Arcobaleno and thus takes an interest in them, but Reborn tells him that the sky Arcobaleno has been missing for quite a while. So how will the sky Arcobaleno test be carried out? Just then, an unknown woman comes to Tsuna’s house with Kyoko and Haru, carrying the orange pacifier. The mystery grows when the woman asks Tsuna to take her, along with Kyoko and Haru, on a tour around Namimori. Does this have anything to do with the tests?
At last, the day of Reborn’s trial rolls around. Reborn tells them to bring all of the guardians to Namimori Island and then leaves. Tsuna notices that Reborn isn’t his usual self, and Tsuna can’t hide his confusion. When Tsuna and the others arrive at the assigned destination, Reborn tells everyone they are to fight him to the death. Reborn mercilessly kicks Tsuna who says he can’t fight him. Even when Tsuna falls unconscious, Reborn commands the other guardians to continue fighting him without regard for the fallen Tsuna.
Tsuna and his friends are told that they did not pass Reborn’s test. If they don’t collect all seven seals of the Arcobaleno, they can’t open the Vongola box. Without the Vongola box, they would lose all means of fighting Byakuran. Will they be given a second chance? Or has the future been closed off to them? Tsuna and his friends are upset, but they somehow muster up the energy to ask Reborn for a second shot. Reborn goes silent upon being asked. But just then, weapons fire and explosives detonate. The last Arcobaleno, Verde appears!
Verde attacks Tsuna and his friends with a weapon of his own invention. They fight back with all their might, but their wounds from Reborn’s test are still fresh, and they are not as powerful as usual. Verde’s intention was to attack Tsuna and his friends while they were weak so that he could steal the Vongola Ring. And this wasn’t just a test. Tsuna and his friends fight back desperately, and Reborn says he and the rest of the Arcobaleno will join in on the fight. As though to add insult to injury, Verde comes after them with a still unfinished box weapon. He even goes after Hibari and Lambo who have returned to Namimori. The Arcobaleno makes a move to help Tsuna and his friends….!
Verde takes Reborn and the Arcobaleno hostage and demands Tsuna to hand over the Vongola Ring. But the future depends on the Vongola Ring. Tsuna and his friends refuse to hand it over, and they head for the unfinished box weapon in order to save Reborn and the Arcobaleno. While watching them struggle against the weapon, Verde is more than ever captivated by the power of the Deathperation Flame. Verde summons forth a new device and activates it. At that instant, Tsuna, Gokudera, Yamamoto, and Hibari feel a kind of magnetic force. However, the other guardians don’t feel a thing. What in the world is this device for…?
It turns out that Verde, this whole time, was not actually Verde, but a robot!? Then where is the real Verde? If they don’t find him, they can’t get his seal. What's more, the real Verde may be plotting yet another attack. Verde himself might not even be hiding within the limits of Namimori. The guardians are overcome with fear. Just then, Tsuna’s hyper senses detect something. Time is running out before they have to return to the future. Will Tsuna and his friends be able to collect all of the seals before time runs out?
Bianchi takes Kyoko and Haru to the Vongola base while leaving Tsuna and his guardians to discuss the upcoming battles with Shoichi. Byakuran sends a holographic image stating he wants to have an official battle between the Vongola and the Milliefiore in a battle of Choice. He reveals to Irie that the Funeral Wreaths and the mare rings they wielded were fakes and he had gathered the Real Six Funeral Wreaths in secret from Irie as he had expected the betrayal.
Tsuna and his friends split up and explore the Namimori of the future. They all coincidentally meet in front of their school, Namimori Middle, and relax in their classroom. Tsuna realizes that to return to their own time, they must defeat Byakuran in the battle of choice. On the roof of Namimori Middle, Hibari encounters the future Dino who insists on training him.
Gokudera brings a newspaper from the current time from which Yamamoto learns about Namimori Middle's baseball team's consecutive losing streak and how the baseball club may be canceled. He heads to Namimori middle and runs into three first year members of the baseball club and offers to train them for the upcoming game.
Tsuna and his friends are assembled to listen to Shoichi's explanation about the upcoming battle which will be played like the game of Choice. He explains that in the game of Choice takes place in a large battle field where two teams attempt to invade the other's mobile bases to defeat their opponents.
Tsuna tells everything he told Kyoko to Haru, who is a bit shocked at the scale of everything, but holds in her sadness until Tsuna leaves. Byakuran hacks into the communications system, giving them the date and location of Choice, and informing them that they will need to bring everyone who came from the past, including Kyoko and Haru.
Realizing that Tsuna and his friends need to become stronger before facing Byakuran, Reborn arranges for Spanner to send them, along with Yuni, back to the past. As they arrive, the day after they completed the Arcobaleno trials, they are met by the other Arcobaleno, who Reborn has called together to train Tsuna and co. Yuni uses her powers to activate Tsuna's Vongola ring, bringing forth the image of the Vongola First.
While Tsuna and his family are observed by their respective Arcobaleno tutors, Colonnello notices that Yamamoto is visibly disturbed by something. The First Generation Rain Guardian, Ugetsu Asari, appears in front of Yamamoto and announces that his trial will take part that night at Nanimori Shrine.
Gokudera, impatient with the trials, begins training at the park early in the morning. While Gokudera is busy looking for Uri who runs away, G disguises himself as Gokudera with Fong buy some times for him. At school, Tsuna and his friends notice that Gokudera has been calmer and more reliable then usual which arouses Tsuna's suspicion.
The Real 6 Funeral Wreaths arrive in Namimori through the use of the teleportation device. Zakuro invades the Vongola base forcing Tsuna and his friends to flee while Squalo buys them time. Tsuna and co decide to hide at Kawahira's realtor from Haru's advice. The successor of Kawahira realtor, a mysterious man, tells Tsuna and his friends to hide inside while he deals with the Funeral Wreaths.
The man introduces himself as Kawahira, whom Tsuna remembers as the man Future I-Pin always mentioned as her regular customer. He then hides Tsuna and his friends in the building. Using Mist illusions, Kawahira is able to send Zakuro away. Elsewhere at Namimori High, Hibari and Dino confront Daisy in battle. Daisy unleashes his Carnage box and stabs his hand through Dino. Hibari intercepts the killing blow and engages Daisy with his Vongola Box weapon, Alaude's Handcuffs.
Hibari defeats Daisy after a short battle and confiscates the Sun Mare Ring. Back at Kawahira's realtor, Yamamoto, Bianchi, Gianni, and Spanner return to the base to search for Squalo. Elsewhere, Byakuran looks at parallel universes and finds where Tsuna and his friends are hiding. Torikabuto manages to enter the realtor and kidnap Yuni by using an illusion and disguising himself as Lambo. Gamma arrives and attacks Torikabuto forcing him to drop Yuni where he then catches her.
Torikabuto releases his carnage box putting everyone around him in a powerful illusion. Chrome's Vongola Box, Daemon Spade's Devil Lens allows her to see through the illusion and helps guide Tsuna's attacks. Tsuna eventually defeats Torikabuto with an X-Burner forcing Kikyo and Bluebell to retreat. Byakuran decides to have the Vindice release Ghost, the final Funeral Wreath, from prison in order to utilize him for the upcoming battle. Later, Yuni suggests to Tsuna and co, that they should hide in the forest.
At the Vindice prison it is revealed that Fran impersonated the Millifiore with illusions and had Mukuro released from prison. Elsewhere, Yuni reveals that her powers of premonition predicted that their final confrontation with Byakuran takes place in the forest and will begin at dawn. While Tsuna and co plan for the upcoming battle, Byakuran reissues the order to have the Vindice prison release Ghost. On the day of the battle, Byakuran and the remaining Funeral Wreaths begin searching for Yuni in the forest. Gokudera, Lal Mirch, and Gamma ambush Zakuro who then releases his Carnage Box.
The explosion resulting from their last attack gives Gokudera the advantage. An attack from Bluebell injures Gokudera and she releases her carnage box intent on killing him. The Varia arrives in time and intercepts the attack. Meanwhile, Ryohei engages Kikyo in battle and is overwhelmed by Kikyo's box weapons, the Cloud Velociraptor. Ryohei asks Lambo if he wants to see Tsuna's mother, reminding Lambo they need to win the battle in order to return home. Lambo releases his Vongola Box in a rage and transforms it into its cambio form, Lampo's Shield. Using the shield, Lambo sends out a surge of electricity defeating the velociraptors.
Kikyo releases his carnage box which allows him to transform his hair into Spinosauruses and engages Ryohei in battle. Ryohei, uses the Cambio Form of his Vongola Box, Knuckle's Maximum Break, allowing him to gain super-human strength, speed, stamina, and reflexes for three minutes. Kikyo is overwhelmed and uses the spinosaurus to buy time until Ryohei's Cambio Form wears off. Three minutes pass, and Kikyo noticing Hibari on the side, sends his Spinosaurses after Hibari and seemingly kills him.
The Varia are simultaneously defeated by the Real Funeral Wreaths when they reveal their secret abilities. Their deaths, including Hibari's, are revealed to be an illusion cast by Mukuro Rokudo who had replaced them in the midst of battle in order to witness the secret abilities of the Funeral Wreaths. As the battle continues, Byakuran sends Ghost into the battlefield.
The Varia and Funeral Wreaths desist from their battles to focus on Ghost. Ghost begins to absorb the Flames from everyone in the battlefield resulting in Bluebell and Zakuro's deaths. Kikyo's reminisces about Byakuran's explanation of Ghost and reveals Ghost was the result of a failed attempt of bringing a Byakuran from a parallel universe into their universe. Tsuna flies towards the battlefield and attempts to use his Zero Point Breakthrough to counter Ghost's absorption of flames.
Tsuna is able to absorb Ghost completely with the Zero Point Breakthrough revealing he was a mass of Deathperation Flames. Byakuran enters the battlefield announcing that all of Ghost's absorbed flames have gone to him. Tsuna, being the only one with sufficient energy left, battles Byakuran alone and is overwhelmed completely. Byakuran creates a translucent hand trapping Tsuna inside whilst crushing his body.
Byakuran coaxes Tsuna into igniting his ring causing a 7^3 reaction which creates an impenetrable barrier whilst drawing Yuni into the same barrier. Byakuran crushes Tsuna into unconsciousness. He then discovers Yuni was attempting to revive the Arcobaleno to restore the balance of the 7^3 and to assist in the defeat of Byakuran. Reborn converses with Tsuna and is able to awaken him by disclosing that Yuni is using her life force to revive the Arcobaleno and will die when the rite is complete. Byakuran mocks Tsuna about his unlucky life and attempts to kill him once more but is saved by Lancia's ring. Tsuna realizes his friends have been with him throughout all the bad times and regains the resolve to fight resulting in Vongola Primo and his guardians to appear from their respective rings.
Yuni explains that like the Mare ring's ability to allow its user to travel through parallel worlds, the Vongola rings allow the past generation to communicate with their current successors. Vongola Primo converses with Tsuna, revealing the rings had a seal on them, allowing them to be split in half for the Vongola Tournament and their current forms only possess powers equal to the Mare ring. Primo releases the seal causing the Vongola Rings to change forms and disappears. Tsuna continues his battle with Byakuran, overwhelming him completely. As Yuni nearly completes the rite, Gamma manages to infiltrate the barrier and embraces her; exclaiming he will die with her. As the rite completes, their bodies disappear leaving behind the Arcobaleno pacifiers. Tsuna and Byakuran's battle climax with Byakuran perishing from Tsuna's X-Burner.
The Arcobalenos are revived. Collonello reveals that Byakuran's defeat caused all of the crimes he did with the knowledge from parallel world to be annulled and removing Byakuran's reign from all the world. Tsuna and his friends say their goodbyes to their friends before returning the past. During their time travel back, the Arcobalenos do three things: Seal the Mare Rings, gives the people involved with the Vongola the memories from their future selves, and turned the Vongola Box animals into rings. At school, Tsuna and his friends return to their daily life and look towards the sky, thankful for Yuni's sacrifice.