OVA
Description
Daisuke Aoki is the homeroom teacher for class 3-1 (later 4-1) at Futatsubashi Elementary School. He experienced an unremarkable upbringing, later becoming an above-average student and athlete. During university, he participated as a substitute in track and field and harbored an unconfessed affection for a female peer who married a senior classmate; he bore no resentment over this.

Starting as a 23-year-old, inexperienced teacher, his idealistic notions clashed with unruly students inheriting mistrust from their previous teacher, Nakamura. His greatest challenge was Rin Kokonoe, a third-grader who aggressively pursued him with sexual innuendo and advances. His lack of experience with women and relationships made him vulnerable to her behavior and to taunts about his virginity from student Kuro Kagami. Aoki's enthusiastic, hands-on, and emotionally involved teaching style contrasted with colleague Sae Shirai's traditional methods and sometimes compromised his objectivity. Senior teacher Kyōko Hōin provided him practical guidance and support.

Aoki's relationship with Rin shifted from shock and discomfort to deep protectiveness after learning she was an orphan. He sought to understand her behavior, and Rin occasionally leveraged her influence to aid his classroom discipline. Following a confrontation near the end of his first year, he acknowledged a strong attraction to her. He struggled to define these feelings, initially interpreting them as paternal love after a comment from Mimi Usa, though he frequently doubted this. His protectiveness intensified, fostering suspicion towards Rin's guardian, Reiji Kokonoe. He temporarily moved in with Rin and Reiji during familial strife but moved out at Shirai's urging due to concerns over appearances.

Ultimately, Aoki admitted his feelings for Rin included romantic attraction. He chose not to act on them or confess, prioritizing her long-term happiness and development, resolving to support her well-being until she matured, accepting she might move on. After Rin turned 16, they reunited and began dating.

Aoki tends to overthink situations and is oblivious to romantic interest from women like Kyōko Hōin. He has difficulty reading social cues, straining interactions with Shirai. Despite these challenges, he maintains a kind-natured and idealistic approach.