Tatsuya Takatsuka appears as a male character in the fourth episode of an OVA series. During middle school, he persistently teased his shy but resilient classmate Chiaki Kuramoto. Despite his provocations, he believed they maintained mutual understanding and trust. His teasing often involved neglecting classroom duties like cleaning to play pranks with friends, sometimes provoking Chiaki's visible anger.

Upon entering high school, Chiaki transformed into a cold, dismissive figure who severed communication and avoided him entirely. Confounded by this abrupt shift, Tatsuya repeatedly attempted to confront her but failed each time. He began questioning whether his past teasing inflicted deeper wounds than he realized or if Chiaki had masked her true feelings during their earlier interactions.

The narrative examines their middle school dynamic, where Chiaki appeared comfortable around him despite her shy demeanor and fogged-up glasses. Juxtaposing this past ease against their fractured high school relationship, the story underscores Tatsuya's bewilderment and introspection over their unraveling bond.