With graduation fast approaching, Touko, a teacher in charge of a final-year class, is having trouble dealing with a group of students who are considered delinquents. To prevent them from repeating the year, Touko continues to provide dedicated instruction every day, and this year, she was able to send every student onto the stage of their dreams without a single student missing. The ceremony ended without a hitch, and Touko was reminiscing alone in an empty classroom, when suddenly, the classroom door was slammed open...