Itsuki is a lonely man who has remained single his whole life. It's no surprise, as he has a bad character and has lived his life without making any effort, believing that "the world is evil." The only thing that gives him comfort is his niece, Moko. When he loses at pachinko and gets annoyed, he calls her over to give him a blow job, and when he gets horny, even though Moko has other things to do, he calls her over and has sex with her, telling her to make him his priority. This is the twisted sex life of a scumbag uncle who exploits the loving Kokoro of his overly obedient niece, Moko, and has sex with her for free.