Saeki Naoki, a third-year high school student, has been in love with his mother Maiko since he was a child. In his dreams, he has crazy sex with his mother every day. But the cold hard truth is that he is unable to marry his mother, much less have sex with her. And so he decided to leave home as soon as he graduated from high school. His mother, Maiko, became unstable at the thought of parting with her son someday and temporarily lost her memory, acting as if Naoki was still a baby. Naoki could no longer control his sanity at the sight of Maiko treating him like a baby and ended up having forbidden sex with his mother. However, his mother thought that the sex with Naoki was "something that happened in a dream"...?