After divorcing her husband, Reika has been raising her son on her own. She takes her son on a trip to a hot spring resort, as he has become withdrawn and is troubled by his relationships with others. She doesn't want to see her son in such a state...she wants to somehow heal him. Her affection for her son turns into forbidden love. She is only trying to encourage her son...but even so, she is consumed by the pleasure of being a woman. At a small inn deep in the mountains, Reika has sex with him again and again, climaxing again and again...a forbidden incest story in which they end up craving each other.