Masashi (Kaito Oyagi) is a 5th grade student in elementary school. His family consists of his father Masato (Kenichi Endo), his mother Kiyoko (Naomi Nishida), younger brother Shigeri (Waku Sakaguchi), younger sister Reiko (Miu Arai) and grandmother En (Sumie Sasaki).

His father Masato works as a timber broker. Their family lives in a large house in Nagasaki. For the first time, Masato tells his son that he can have a birthday party at their home. Masashi is completely thrilled, but Masato and Kiyoko know that this will also be the last birthday party for Masashi at their home. Masato's financial situation has collapsed. Masashi does have his birthday party with friends at his home, but, on that night, Masato informs his family that will move.