Hitomi, a mother who lacks motherhood, has no interest in the suffering of her only son, Yusaku. Despite Yusaku desperately searching for the meaning of living in a life that feels like chewing on sand, Hitomi has bodies with men one after another just for the sake of pleasure. Seeing Hitomi's attitude, which doesn't look bad even when Yusaku reprimands her, Yusaku begins to feel that even the meaning of the taboo between mother and child is lazy and worthless...