``Suzu'' is a normal, serious-looking girl who can be found anywhere. Suzu's parents are going on a trip for about a month. At the same time, her cousin ``Jun'', who lives in a rural area, decides to take advantage of his summer vacation to take a summer course for his university entrance exams by lodging in an empty room at ``Zuzu''s house. In this way, a strange semi-cohabitation life begins for a month during summer vacation, but after one summer...