OVA
Description
Daisuke Aoki is the protagonist of the story, a young and earnest elementary school teacher. He is 23 years old and has just graduated, landing his first teaching position at Futatsubashi Elementary School, where he is assigned as the homeroom teacher for class 3-1. Physically, he is a young Japanese man of average build, standing 175 cm tall and weighing 64 kg, with short black hair and glasses that are a defining feature of his appearance. He strives to be the kind of teacher who is dependable and approachable, like a big brother to his students. His blood type is A.

Aoki's personality is characterized by a strong sense of enthusiasm, justice, and a hands-on approach to his work. He is fundamentally a kind and responsible individual, but he is also notably naive, innocent, and prone to overthinking situations. His lack of life experience, particularly with women and romantic relationships, is a significant part of his character; he is a virgin and has never had a girlfriend. This inexperience makes him particularly vulnerable to the precocious and sexually charged advances of his student, Rin Kokonoe, and the barbed comments about his virginity from another student, Kuro Kagami. Despite his best efforts to remain professional and objective, his emotional attachment to his students often leads him to clash with the stricter, more traditional teaching style of his colleague, Sae Shirai.

His primary motivation as a teacher is to genuinely help and connect with his students, an ideal that is immediately tested by the unruly class he inherits and the complex personal troubles of certain students. Aoki’s role in the story is that of the protagonist who must navigate the challenges of his first teaching job, which are far more complicated than he ever anticipated. His journey involves learning to understand the hardships faced by his students, particularly Rin, whose aggressive and inappropriate behavior initially troubles him greatly. After learning that Rin is an orphan, his attitude softens, and he becomes determined to understand and support her. This evolves into a deeply complex and central relationship. He struggles to define his feelings for her, initially trying to see her only as a child, then realizing he feels a protective, fatherly love for her. By the end of the story, he ultimately comes to terms with the fact that he has developed a genuine romantic attraction to Rin, though he resolves to maintain his principles and wait until she is older.

His key relationships are central to his development. His bond with Rin Kokonoe is the most significant and complex, moving from initial shock and discomfort to deep affection and protectiveness. He also shares an important professional and personal bond with his senior colleague, Kyōko Hōin, who provides him with practical advice, teaching suggestions, and moral support as he learns to be an educator. His relationship with Sae Shirai is one of constant butting heads, as her strict, distant style conflicts with his heartfelt, involved approach. He also becomes increasingly suspicious of and confrontational with Rin's guardian, Reiji Kokonoe, as his protective instincts for Rin grow.

Throughout the series, Aoki shows significant development from an inexperienced, idealistic novice into a more capable and understanding teacher. He grows more adept at handling his class and comprehending the difficult realities his students face, while constantly wrestling with his own unresolved emotions. His personal journey culminates in him moving in with Rin and Reiji at one point to keep the peace and later accepting his own romantic feelings for Rin, choosing to wait for her to grow up. In the end, several years later when Rin is 16, they are reunited and finally begin a romantic relationship together. In terms of notable abilities, Aoki was an above-average student and athlete in his youth and served as a substitute for a university track and field club. However, his most significant ability is not athletic or intellectual, but his seemingly unshakable enthusiasm, his capacity for empathy, and a deep, persistent desire to be a good teacher and a positive influence on his students.