Protagonist's summer vacation has just begun, but due to certain circumstances, he find himself without a place to stay. Fortunately, he learns about a distant relative (a college student) who is looking for a roommate nearby. The protagonist moves in, only to discover that there are already three voluptuous women living there, making it one male and four females in the house. It's like infiltrating an all-female dorm! This rings the start of our virgin protagonist's exciting days.