Ken, the nephew of a student taking entrance exams, ends up staying at the house of his mother's younger sister, Mako, who lives in Tokyo. However, her big-breasted Mako is always without a bra at her house, and her big breasts and her nipples, which are clearly visible even through her loungewear, are so naughty that I can't really study her at all. She lives with her aunt, who unconsciously commits erotic terrorism, and Ken's patience is about to be exceeded when she... You know, my...