A young sister and brother pair lose their parents in an earthquake. The sister and brother go live with their aunt and uncle. Although they are well cared for, they decide to hide the deaths of the parents from the brother and the sister carries great guilt over their deaths.
One day, Hiroko accidentally starts a small fire while she is cooking. Although it does not lead to a serious incident, it does result in her going to stay with her eldest daughter, Yuko, for whom Hiroko has never been the mother she wanted.
