Since their divorce several years ago, Kaoru and her only son, Masao, have been living together. One day, the couple finally have some financial security and decide to move out of their rundown one-room apartment. Kaoru and Masao cannot hide their joy at the spaciousness of their new home. Kaoru and Masao have been secretly engaged in an incestuous relationship, and in this spacious house, they want to have sex to Kokoro's content. Then, on the night that comes, Kaoru is seen bouncing more than usual as she cums on Masao's dick...