Nagi Seishiro is a second-year high school student. He is a boy whose habit is to say, "It's a pain in the ass," and he lives his life listlessly. Until his partner, Mikage Reo, discovers his talent in the "Blue Lock," a dormitory for training strikers that aims to win the World Cup for Japanese soccer.

Aoi and Haru and secretly dating. However, Aoi notices that Haru has been worried about something, and the next day, he sees her fall from the roof of the school. He then discovers that she put a chart of relationships into his locker, and marked five of them as "clowns" who are trying to kill her.