On the day of a group project presentation, college senior Lee Seung-hyeon is falsely accused of sexual harrassment on the subway, causing him to miss the presentation and fail the class. Desperate to salvage his GPA before graduation, he scrapes together enough money to enroll in summer classes, only to find himself stuck in another group project. To his horror, one of his groupmates, Seo Chaejun, turns out to be the very person who accused him of sexual harrassment. Now, during what should have been a peaceful summer break, Seung-hyeon is forced to confront his worst nightmare. "What did I do that was so wrong to deserve spending this precious summer break of my senior year dealing with this lunatic?"