Suzu is an ordinary, serious-looking girl. But her parents are going on a trip for about a month. During that time, her cousin Jun, who lives in the countryside, is taking summer classes for his university entrance exams and staying in a spare room in Suzu's house. Thus begins a strange semi-cohabitation life for a month during the summer vacation, but after one summer, the big-breasted honor student who was a beginner at streaming transforms into an incredibly lewd bitch. #YoroP