Asano Haruki, a self-proclaimed plain middle school third-year, lives an isolated school life, often whispered about as a scary delinquent due to his natural brown hair and bad eyes. His only constant companion is his childhood friend, Fukase Shiho, a popular, beautiful, and academically brilliant basketball ace. Haruki secretly harbors deep feelings for Shiho and diligently studies to enter the prestigious Izumido High School alongside her, a goal Shiho seemingly shares. However, Haruki's school days are marked by loneliness, as Shiho avoids him in public, a fact Haruki attributes to her social standing.
Haruki often escapes to the school rooftop, where he encounters Endou Seina, a sharp-witted, outwardly delinquent girl with blonde hair and piercings. Seina, who also skips class, quickly perceives Shiho's true nature, warning Haruki about her self-centeredness and lack of genuine care for their relationship. Haruki's past is revealed: he became isolated after defending Shiho from an upperclassman, Chida, last year, an act of self-defense that cemented his delinquent image.
The turning point arrives when Haruki, after achieving good test scores, overhears Shiho badmouthing him to her friends. She calls him "creepy," "violent," and "lowest," revealing she manipulated Chida into harassing her to set Haruki up for a fight, all to distance herself from him and protect her image. Devastated, Haruki confronts Shiho, echoing her cruel words, and decisively severs their relationship, calling her "Fukase" as a final act of rejection.
In the aftermath, Seina becomes Haruki's unwavering support. She pushes him to aim for Kaisei High School, a top-tier institution, and helps him study, significantly improving his grades. Haruki's father announces a transfer to America, leading Haruki to move into his own apartment for high school. Both Haruki and Seina undergo a "reverse high school debut" for Kaisei: Haruki dyes his hair black to shed his delinquent image, and Seina transforms into a refined, black-haired beauty, though her blunt personality remains.
At Kaisei, Haruki finds himself no longer isolated and even receives a confession from a classmate. However, Shiho's betrayal has left him with a "female phobia," causing him to panic during intimate interactions. Seina, now a popular and brilliant student, initiates "exposure therapy," using physical closeness to help him overcome his trauma. Haruki's new friend, Shiraki, develops a crush on Seina, stirring complex feelings and jealousy in Haruki.
During the cultural festival, Haruki, playing a ghost in his class's haunted house, has a final, emotional encounter with Shiho, who apologizes and reveals she quit basketball, feeling unworthy. Haruki encourages her to find her own path, and they part ways for good. Later, Shiraki asks Haruki to help him confess to Seina, which Haruki initially agrees to, but his growing jealousy and confusion lead him to push Seina away, causing her hurt.
The next day, Haruki falls ill. Seina, having rejected Shiraki, comes to his apartment to care for him, revealing she waited for two hours. During their conversation, Seina's "exposure therapy" culminates in a kiss and intimacy. Haruki realizes his female phobia has subsided, and his heart races not from fear, but from genuine affection. When confronted by classmates about their relationship, Seina boldly declares they are dating. Haruki, though still slightly confused by Seina's "true feelings," acknowledges his love for her, resolving to confess when she's ready to reciprocate with her whole heart.
