Raised in a single-parent household, Kentaro has long harbored feelings for Sayuri, his friend's mother. As he matures into a man, his childhood admiration for her maternal warmth transforms into deeper, more intense emotions. One day, he is caught spying on her while she's bathing and rummaging through her lingerie. Confronted and scolded, Kentaro can no longer hold back. "I'm in love with you!" he confesses passionately. This bold declaration changes their relationship forever.