Five years after visiting his relatives' home, Yuuji found himself captivated by his aunt Rinko, whose mature allure had only intensified despite the passing years. He felt his heart race at her presence. One day, he discovered her freshly discarded underwear in her room and indulged in masturbation while inhaling its scent. When Rinko learned of his act, she confronted Yuuji with her semen-stained panties, turning it into their shared secret, and began seducing and teasing his young body. Through these intimate exchanges, their forbidden relationship deepened further.