My daughter-in-law’s mother comes to Tokyo from Kochi while my wife is hospitalized, leaving me to live alone. With just the two of us under one roof, my buxom fifty-year-old stepmother begins to treat me with tender affection, exposing her cleavage and drawing me closer. As my wife remains away, the bond between us grows tighter, evolving into a deeply intimate and lustful relationship. This new daily life with my stepmother becomes a mixture of warmth and seduction, marking the beginning of a forbidden closeness.