Dan Oh is a high school student. One day, she suddenly realizes that something is going on with her. She suddenly loses her memory and her personality changes. She goes to the doctor, but the doctor says that she is completely normal. However, she now can see into the future! What is going on with her?
Dan Oh realizes that her role in the comic book is to make the lead characters fall in love, and she hates it. Even she smashes the plaster casts, it goes back to normal since that is not intended by the writer. Dan Oh asks Dried Squid about the black hole she saw at the library, but Dried Squid says that it’s a dangerous thing.
Dan Oh finally finds the guy she was looking for, but she suddenly teleports to the hospital. Dan Oh meets Do Hwa at the hospital, and Do Hwa tells Dan Oh that she has been acting strange these days. Do Hwa becomes aware of himself, and Dan Oh tells him that he is in the world of comics.
Dan Oh gets lost in the mountain while the couple night trekking, and she is scared of being alone in the midst of the mountain. At that moment, Number 13 comes to Dan Oh. Dan Oh realizes that the story has changed because of Number 13, and she names him Day since he changed her day.
Dan Oh tells Kyung that she wants to break up with him. Also, Dan Oh is determined to change the storyline of the comic, but Dried Squid tries to stop her, saying such a change might destroy the world of the comic. Meanwhile, Nam Ju's parents visit the school and plan out Nam Ju's birthday party.
Dan Oh tells Kyung that she never liked him. Like Dried Squid said, Haru’s pain gets worse when the story changes. Kyung tells Haru that he is just toying with Dan Oh, and Haru gets mad at his attitude. Meanwhile, Haru decides to be the only person who can change Dan Oh’s fate.
Kyung tells Dan Oh that he knows about the book “Secret”. Haru disappears all of a sudden, and the students in Seuli High School don’t remember him at all. Dried Squid tells Dan Oh that it is because of her, and Dan Oh doesn’t know what to do. Kyung tries to make Dan Oh feel better, but it’s not easy.
Haru becomes popular in Seuli High School. Nam Ju announces that Ju Da is the only woman for him from now on. Dan Oh decides to accept her own fate and forget about Haru and her struggles to change the story. Meanwhile, Haru keeps having a dream about Dan Oh.
Haru returns to his old self, and Dan Oh and Do Hwa are happy to have the old Haru back. Dan Oh is glad to have Haru back, but she is also afraid to lose him again. Meanwhile, Dan Oh and Haru play hooky and they find an antique shop.
Kyung finds the book which Dried Squid burnt, and Dried Squid tells Kyung the former work of the writer has nothing to do with their current world. Kyung is mean to Dan Oh on the stage, and he regrets it after the stage. Meanwhile, Kyung tells Haru that he can’t beat him since he is a mere extra.
Kyung is worried about Dan Oh because she just left the hospital, and he recalls his old memory with Dan Oh. Dan Oh comes back to school. Dan Oh is happy when she is with Haru, but Kyung isn’t happy to see her like that. Meanwhile, Kyung asks Dan Oh if she likes Haru because he can change the stage.
Dried Squid tells Kyung that he lost everything because of him. Kyung sees the comic book and tells Dan Oh that she will call of their engagement. Haru tells Dan Oh that they have known each other for a long time. Meanwhile, Ju Hwa suggests Dan Oh that she should get the surgery.
In “Trumpet Creeper”, Haru witnesses Dan Oh’s death. He doesn’t want to admit that the same thing is happening in “Secret”, but Dried Squid tells him that the story is repeating itself. Meanwhile, Dan Oh’s condition gets worse, and she wants to keep it secret from Haru.
Do Hwa and Haru try to change Dan Oh’s story. Haru goes to the hospital and switches Dan Ohs’ medical chart to another person’s. Dan Oh doesn’t need to have surgery anymore, but Kyung tells Haru that Dan Oh will die because of him. Kyung warns Haru to stop changing the story before he puts Dan Oh in bigger danger.
Dan Oh can’t remember anything that happened in the shadow, and she is not aware of herself now. Everyone in the school gets to know that Nam Ju was born out of wedlock, and they start to ignore him. However, Ju Da stays by his side even in the shadow. Meanwhile, Su Hyang is aware of herself.
Haru wants to do everything for Dan Oh. Do Hwa realizes that the real Dan Oh is back, and he is happy to have his friend back. Dried Squid suggests Haru and Kyung that they should all forgive each other. Meanwhile, Jun Hyun tells Haru that he is envious of his bravery to change his own fate.
