Continuing from the previous episode, Shinichi added that because of Kogoro's idea to give a kiss to the bride and groom, someone died. However, Kogoro counters him back that Shinichi was also going to get HIS first kiss, which makes Ran gets suspicious about it. Before the case starts, Ran and Sonoko manage to win Shinichi (by cheating) and his penalty is to accept any favors from anyone for the whole day. Suddenly, Kogoro calls in that he needs his help to go on a deep-undercover investigation, which he realize a bit too late as he realize it's a ruse. Turns out that a married couple, Motoki Kensuke and Shimabara Kanon are celebrating their marriage in Kensuke's restaurant 'Diavel's Kiss' and Kogoro asks him to help him make preparations for the wedding. Not breaking Ran's promise, he does so. During his time, he receives a threat telegram that was supposed to be for one of the couples. As the wedding starts, after his speech, he ask the couples to kiss while Shinichi was still thinking that the telegram was just a prank. However, one of the guest, Masumoto Nana, who was drunk, dies from poison after drinking some of the guests' drinks. As Sato and Takagi arrived at the scene, it was revealed that Nana died from allergic reaction to soba. After further investigation, Shinichi finally reveals that the culprit was the bride Kanon. Kanon figures out that Kensuke's having an affair with Nana so before the kissing ceremony, she eats curry with soba in it and uses Kensuke after giving a kiss to him, transferring the soba to Kensuke's lips. Before being taken away by the police, Kogoro lectures Kanon that Nana had envied her due to being in love with a man Kanon truly loves as both Nana and Kanon hold a complex to each other. If both have quarrel and more honest, both of them would be true friends in the end than having grudges towards each other. Suddenly, after the case is over, Ran came over hearing about the 'kiss' part and beats both Shinichi and her father down.
B
蘭と園子に神経衰弱で負けて「今日1日他人の頼みを断らない」という罰ゲームを課せられた新一は、小五郎の頼みで結婚式の手伝いをすることになるが、その結婚式の裏側では新郎新婦の本木とかのん、その友人であるナナの間で複雑な恋愛事情が渦巻いていた。やがて始まったパーティーで、ナナが他の友人のカクテルを横取りして飲んだ瞬間、ナナは突然苦しみだして死亡する。しかし、カクテルから毒物は検出されなかった。入力したキーワードは「キス」。
