Living together as a trio with his wife and her mother, Chisato, Pureiji enjoys a harmonious and cheerful daily life. One weekend, while his wife Minami attends a friend's wedding, Pureiji finds himself alone at home. That night, fueled by alcohol, he confesses to Chisato that she reminded him of his first love when they first met—an innocent remark that sparks unexpected tension. Overcome by long-suppressed emotions after years since the death of her husband, Chisato gives in as Pureiji makes an assertive advance. This sudden turn of events marks the beginning of a forbidden new relationship.