Since she could think, Mariko wondered why she didn't resemble one of her parents. She always had the strange feeling that she is not their daughter. One day, after she comes back home from boarding school and enjoying her parents' gentle and warm welcome, she quickly falls asleep, and wakes later on up, outside in the cold, while seeing her home burn down. The firefighters manage to save her father, but not her mother. Years later, Mariko sees a reportage of students from the Tokyo University, where one girl is being interviewed. This one girl looks just like her. Mariko is shocked by this news, but sees herself even more confirmed now, that she is not the true daughter of her parents.