One day, when the mother (Yumi) comes home from work, her son (Tatsuya) is exhausted because he plays games all the time and never cleans up. He takes a nap on the sofa to get some rest. Hungry, Tatsuya tries to wake his mother up by shaking her, but she doesn't wake up. However, seeing her voluptuous body, Tatsuya's desire is ignited and he starts caressing his mother's body...