Hikari Hazakura, 22, teaches physical education at Kawanuma Higashi High School while advising the student council and swim team. Her athletic build measures 164 cm tall, 53 kg weight, and 88-56-87 proportions, maintained through amateur swimming. Tanned skin displays clear swimsuit tan lines, paired with dark brown hair, brown eyes, and lively expressions featuring playful gestures. Energetic, cheerful, and tomboyish, she frequently teases and pranks others—especially childhood friend and neighbor Takashi Takahashi, nicknamed "Taka." Though outwardly confident and mischievous, she reveals shyness in romantic contexts, occasionally masking genuine feelings with humor in tsundere-like fashion. Students admire her approachable, fun-loving nature despite occasional clumsiness. Her background revolves around a lifelong friendship with Takashi, originating in their shared apartment complex. She often initiated playful physical contact like testing wrestling moves or dressing him in girls' clothing, fostering a sibling-like dynamic. Repeated accidental intimate encounters gradually shift her view of Takashi beyond friendship. During a joint festival between Kawanuma Higashi and Nishi High Schools, her emerging romantic feelings surface, embracing vulnerability. Professionally, she coaches swimming and mentors students, leveraging athleticism and enthusiasm to command respect. Initially dismissive of Takashi’s maturity, she later acknowledges his growth and enters a romantic relationship, though struggles to relinquish control. Key events include her involvement in the "Kurisu Kurumi Arc" at Sakikawa High School and mutual acknowledgment of feelings with Takashi, transitioning their bond from sibling-like to romantic.