Sōta Takanashi is a 16-year-old high school student working part-time at the Wagnaria family restaurant, recruited by Popura Taneshima. Her petite stature and cute appearance appealed to his obsession with small, adorable things, a trait developed from being tormented by his older sisters. This upbringing fostered his dislike for older women, though he makes exceptions for those he deems sufficiently small or childlike, like Popura, despite her being older. His family includes four sisters: Kazue, Izumi, Kozue, and Nazuna. With his father deceased and mother largely absent, he shoulders household responsibilities, cooking and managing finances while caring for the frail Izumi and managing Kozue's alcoholism. His younger sister Nazuna, nearly as tall as him despite being in elementary school, assists him and offers advice.

As a child, frequent dressing in his sisters' hand-me-downs created lasting resentment for cross-dressing. Nevertheless, he adopts the persona "Kotori" to assist Mahiru Inami, wearing a pink wig, feminine attire, and padding to achieve a convincing feminine appearance admired by Popura and male customers. At work, he uses a hand extender to interact with Mahiru, who has severe androphobia and instinctively punches men. Though trained in Aikido by Kozue and possessing the durability to withstand Mahiru's structurally damaging punches, he refuses to retaliate against women.

He balances responsibility and eccentricity. Diligently managing work, school, and home duties, he displays bluntness, often unintentionally insulting coworkers—like calling manager Kyōko Shirafuji "old," leading to punitive scheduling. He romanticizes small things, comparing Popura to insects or water fleas, which others find demeaning. Initially oblivious to Mahiru's romantic feelings, he gradually develops his own, misinterpreting her jealousy over Kirio Yamada as masochism. His efforts to cure her androphobia include confronting her father as Kotori, criticizing him for causing her trauma. Over time, he acknowledges his feelings, leading to awkward interactions, dating, and a confirmed relationship.

His coworker relationships are complex: he protects Popura like a younger sibling yet scolds her for errors; he respects Jun Satō as the restaurant's sole "normal" employee; he navigates Yachiyo Todoroki's katana-wielding intensity and Kyōko's grudges. Kozue's drunken visits to Wagnaria embarrass him, while Nazuna's occasional assistance highlights her maturity. His growth involves accepting Mahiru's height, contrary to his preference for smallness, and overcoming his aversion to older women through their relationship.