When Shizuka remarries Genji, her grown son Susumu suddenly has a stepfather who openly resents him, leaving the household tense and uncomfortable. Susumu endures Genji's constant jabs at the dinner table, with his mother as his only comfort—especially since Shizuka and Susumu had already crossed the line into an incestuous relationship. No longer able to openly seek his mother's affection after Genji moves in, Susumu's desire keeps building until he begins reaching for her body beneath the kotatsu while all three sit together...