拓哉打算和女友京子跨越最后一道防线时，没想到京子却说拓哉的性器官很可爱，京子让拓哉深受打击，两人的初体验不欢而散。此时，拓哉的学长西川找他去兜风，从箱根出发往伊豆的途中，西川结识了一位名叫真理的女子，西川为了想和真理有进一步的关係，便谎称车子抛锚无法上路，要求拓哉去附近寻找住宿的场所。三人还在路上出手相救了遭恶男调戏的藤子，原来藤子是经营小木屋民宿的老闆娘，于是三人顺理成章住进了藤子的小木屋...

Yasuo is staying at home with his father, Tassuke, who is just like his uncle.　　However, Tase’s daughter, Seiko, has an outspoken affinity for Yasuo from the first day.　　Seiko’s aggressive body atta...