Days spent alone with his mother bring a profound change in Kenji's heart. The care and warmth he once shared with siblings now feels like mere loneliness. Toko, struggling to adjust to the sudden quiet after the family bustle, feels a growing emptiness within. Witnessing his mother's loneliness, Kenji realizes how much he's always shared her affection with his brothers, and begins craving her love exclusively for himself. As their bond transforms into something deeper and more intimate, a desperate, forbidden closeness takes root between mother and son.