A teacher who is pushed by a student on graduation day and then travels back in time to his classroom on the day of the opening ceremony a year ago, faces his student seriously in order to find out the truth in this new age school drama.

Rina Kujo (Mayu Matsuoka) is a chemistry teacher and the homeroom teacher for the 3rd grade D class at Horai High School. She doesn't have a bond within of her students. On the school's graduation day, Rina Kujo is pushed from the 4th floor and falls down. She is able to glimpse a school uniform sleeve on the person that pushed her. At that time, she wonders why she was pushed and that she does not want to die. The next moment, Rina Kujo is standing in front of her students and she has travelled back in time to one year earlier. She knows that one of the 30 students in front of her will try to kill her in a year. To find the truth about what will happen and to avoid her death, she approaches her students with all her heart. Meanwhile Kanau Ugumori (Mana Ashida) is one of Rina Kujo's students in the 3rd grade D class. She is a model student, but she experiences a miserable school life due to her classmates targeting her.—AsianWiki