Miwa and her son Shiro lived together as a family of two. After her divorce from her husband, she had grown distant from any romantic relationships with men. One day, she invited her boss from her part-time job over to her home, only to be suddenly propositioned by him. Witnessing this shocking scene, Shiro confessed to his mother that he also wanted to be intimate with her. Miwa had no intention of rejecting her son's desire, and thus began giving him real sex education. As their forbidden relationship progresses, Miwa struggles with deepening inner conflict—caught between passion and dignity, torn by her feelings as a mother. A story of intense emotion, taboo, and maternal love intertwined.