Kyoko Himeji sports shoulder-length brown hair and piercing blue eyes, her teenage frame belying a past marked by significant change. Once overweight in middle school, she channeled an unrequited crush on a male teacher into rigorous self-reinvention, shedding weight to become one of her friend group’s tallest members. Her buoyant, outgoing nature masks deeper complexities—she casually references her sexual experiences, having been the first in her peer group to lose her virginity, yet her romantic pursuits often leave her vulnerable to exploitation due to a tendency to yield to temptation. This contrasts with her fiercely protective streak toward Ikue Ogawa, a petite friend frequently mistaken for her daughter amid their stark height difference.

Academically gifted, Kyoko outshines her social circle intellectually, though she rejects any association with Eriko’s “Moron Group.” Lingering insecurities from her former self-image and unresolved feelings for the narcissistic teacher Odagiri subtly color her interactions and self-worth. Her journey centers on reconciling the social implications of her physical transformation, shielding those close to her, and grappling with how peers perceive her maturity against the backdrop of her choices and vulnerabilities.