Three young people, Irie, Sugiya and Asami, decide to share a room together one summer. All three of them experience sadness, love and friendship as they fall in and out of love. They all become a vital part of each other's life, but at the end of summer vacation, they go their separate ways. Sugiya returns home, Asami leaves Tokyo and returns to the country and Irie remains in the room they had shared, as if nothing had happened over the last 40 days during summer.