Kotaro Enomoto begins his high school journey as a first-year student in Sakuragaoka High School's Class 1-1, progressing to his second year. He actively participates on the school's men's soccer team, securing a regular position in his sophomore year. He shares a home with an older sister, Natsuki Enomoto, who attends the same school as his upperclassman; their relationship involves frequent bickering yet underlying mutual support. The Enomotos live next door to the Setoguchi family, fostering a long-standing neighborhood connection. Yu Setoguchi, Hina's older brother, observes Kotaro and Natsuki's arguments with occasional annoyance, viewing their dynamic akin to a parent-child relationship. Physically, Kotaro possesses brown eyes and brown hair. His first-year haircut is short, featuring bangs that reveal his forehead. By his second year, he grows taller, sporting longer hair that reaches the back of his neck, with bangs covering more of his forehead. His standard school attire consists of an unbuttoned uniform jacket over a white shirt, consistently layered with a partially visible orange undershirt. Personality-wise, Kotaro exhibits high emotiveness, a quick temper, and a loud demeanor. He displays strong protectiveness towards friends and loved ones, particularly concerning Hina Setoguchi's well-being, proactively addressing sources of her distress. He supports platonic relationships earnestly. His middle school past includes frequent involvement in physical altercations. His deep-rooted childhood friendship with Hina Setoguchi stems from their families' close proximity. Kotaro develops unreciprocated feelings for her during their youth, though Hina initially perceives him only as loud and bothersome. He consistently prioritizes her happiness, often intervening in situations affecting her while concealing his feelings until confessing during their second year of high school; their relationship evolves into dating afterward. Kotaro experiences jealousy regarding Hina's crush on upperclassman Koyuki Ayase, confronting him following Hina's rejection. Koyuki advises Kotaro to pursue his own romantic interests, leading to a later reconciliation observed during collaborative gardening. Kotaro maintains enduring friendships with classmates Ken Shibasaki and Kodai Yamamoto since at least middle school, forming a group nicknamed the "Idiot Trio." Ken frequently teases him about Hina, requiring Kotaro to rein him in, while Kodai seeks his advice and provides reassurance. Another middle school connection is Arisa Takamizawa; Kotaro assists her during a bullying incident by cleaning her vandalized desk at Ken's request, forging a lasting friendship. Arisa later teases him about his feelings for Hina and actively encourages their relationship. His given name incorporates the characters for "tiger" (虎), "thick/big" (太), and "melodious/cheerful" (朗). His surname combines "lotus tree/nettle tree" (榎) and "base/source" (本).