Kotaro Enomoto is a first-year student at Sakuragaoka High School and the younger brother of Natsuki Enomoto. He has been a childhood friend of Hina Setoguchi for as long as he can remember, having grown up alongside her and sharing a close bond. Kotaro is an active member of the soccer team and presents himself as a mischievous, energetic jock with a loud voice and an emotionally intense personality. He often feigns a brusque and dismissive attitude, which serves as a front for a deeply caring and protective nature. Around Hina, he becomes notably shy and struggles to express his true emotions. His primary motivation is his long-standing, unrequited love for Hina. Although he is hurt by her feelings for an upperclassman named Koyuki Ayase, Kotaro privately vows to prioritize Hina's happiness above his own. His desire to remain by her side drives him to study diligently so he can gain admission to the same high school she plans to attend. Within the story, Kotaro occupies the role of the conflicted childhood friend, caught in a one-sided love triangle. He silently observes Hina's pursuit of Koyuki, experiencing jealousy and heartbreak but refraining from acting on his own feelings out of respect for her choices. Key relationships include Hina Setoguchi, the object of his deep affection; his older sister Natsuki, with whom he shares a bickering but affectionate sibling dynamic; Koyuki Ayase, whom he regards as a rival; and his classmates Ken Shibasaki and Kodai Yamamoto, with whom he has maintained enduring friendships since middle school and together form a trio nicknamed the Idiot Trio. Kotaro undergoes significant development over the course of the narrative. Initially unable to confess his love, he silently supports Hina from the sidelines. A turning point occurs when he witnesses Hina heartbroken after she confesses to Koyuki; unable to contain his emotions, he openly declares his love for her, admitting his feelings to himself and his friends for the first time. This breakthrough eventually leads him to directly confess his love to Hina. His notable abilities include athleticism as a soccer player and a strong, determined will that enabled him to successfully improve his academic performance and gain entry into a competitive high school.