Kotarō Enomoto is a Japanese high school student at Sakuragaoka High School with brown hair, red eyes, and a height of 1.60 meters that increases slightly over time. His appearance evolves during high school, his hair growing noticeably longer by his second year. He typically wears his school uniform with the top open, revealing an orange undershirt beneath the white school shirt. Coming from a family long neighbored and close to the Setoguchi family, Enomoto shares a childhood friendship with Hina Setoguchi. He harbors a long-standing, unrequited romantic interest in her, initially concealed. Prioritizing Hina's happiness, he actively supports her during emotional difficulties. Their relationship deepens gradually, leading Enomoto to confess his feelings near the end of his first year; they begin dating in their second year. Enomoto possesses an emotive and quick-tempered personality, often reacting loudly or with annoyance. He exhibits a protective streak towards friends and loved ones and frequently engaged in physical fights during his youth. He forms the "Idiot Trio" with friends Ken Shibasaki and Kōdai Yamamoto. Within the group, they tease each other, particularly about his feelings for Hina; Enomoto often works to keep Ken in line, while Kōdai provides him advice and reassurance. Family relationships are significant. His older sister, Natsuki Enomoto, attends Sakuragaoka as his upperclassman; they frequently bicker and fight but maintain underlying mutual support. He views Yu Setoguchi, Hina's older brother and another childhood acquaintance, through a lens resembling a parent-child dynamic due to Yu's tendency to supervise him and Natsuki. Enomoto develops a rivalry with Hina's upperclassman crush, Koyuki Ayase, fueled by jealousy over Hina's feelings. This tension escalates when he confronts Koyuki after Hina faces rejection, resulting in an emotional exchange where Koyuki advises him to pursue his own feelings to avoid regret. Despite this rocky start, their relationship later improves, seen in activities like gardening together. His friendship with Arisa Takamizawa dates to middle school, beginning when he helped her deal with bullying by cleaning her vandalized desk at Ken's request. Arisa frequently teases him about his affection for Hina and actively encourages their relationship. Enomoto joins the Sakuragaoka men's soccer team upon entering high school. His dedication leads to a promotion to a regular position on the team during his second year. The etymology of his name reflects symbolic meanings: "Kotarō" incorporates characters for "tiger" (虎), "thick/big" (太), and "melodious/cheerful" (朗), while "Enomoto" derives from "lotus tree/nettle tree" (榎) and "base/source" (本).