Natsuko, who raised her son Ko-suke single-handedly, has finally decided to get married. However, Ko-suke, who secretly admired his mother, could not shake off those feelings until the very end... On the eve of his wedding, as Ko-suke struggles with his new life, his mother tells him, 'I just want you two to be happy...' and gives her son her final lesson. Overwhelmed by selfless love, Ko-suke experiences repeated ecstasy from the unfamiliar pleasure, growing increasingly excited. And so, the mother and son, having tasted forbidden delight, find themselves trapped in a whirlpool of desire...
