After returning home from school, Hiroshi stops by his friend Tooru's house and accidentally catches Reina masturbating in the kitchen. In that instant, Hiroshi is deeply shaken—Reina's image lingers in his mind, refusing to fade. Driven by obsession, Hiroshi actively seeks another encounter with her, eventually toying with her while reveling in her growing arousal. Recalling her in a yukata, he finally gives in and touches her body. The story carefully portrays Hiroshi's shifting emotions and his irresistible attraction to Reina.