Miki, who has grown into a completely grown-up woman, has a hopelessly perverted brother who is always hiding in the house and peeping on her when she masturbates or when she brings her boyfriend over and has sex with him. One day, the brother sneaks into his sister's room to try to have sex with her at night, but is found out. From that day on, he becomes his sister's slave and is forced to perform cunnilingus on her like a butter dog on a daily basis... Such a brother and such a sister!
