Etsuko Mano is 52 years old. Her husband works at a trading company and is currently on a business trip overseas. She lives alone with her eldest son, Tsutomu, but has found it increasingly difficult to connect with him as he has grown older. Recently, Tsutomu has been locking himself in his room and rarely comes out, causing her great concern. Worried that he might be suffering from depression, she decides to check on him by visiting his room.