Living alone in a Tokyo neighborhood, Sayoko had avoided relationships since losing her husband five years earlier. When an old friend contacted her asking if her son Masaru could stay for a few days while visiting Tokyo, she reluctantly agreed. Meeting Masaru for the first time in three years, Sayoko began sensing an unsettling gaze from him, stirring emotions she couldn't suppress—leading her to masturbate in private. But Masaru accidentally discovers her in the act. How will their relationship change from this moment on?