After her husband's death, Toko struggles alone to keep the family construction company running. Her adult son Ichiro works hard as its successor, but the business finally collapses. When their electricity is cut off on a snowy night, mother and son press their bodies together for warmth. Ichiro holds her tightly and promises to protect her. Seeking comfort in each other's heat, they eventually undress, press bare skin to bare skin, and kiss, crossing the line into incest and creampies.