The novel opens with a flashback to Hiroshi's departure from his mother's house. Hiroshi and his mother are discussing the events of the previous day, and Hiroshi tells his mother that he wishes he had stayed longer with his mother. The flashback then shifts to the present, where Hiroshi asks his mother why she is not looking harder for his sister. His mother replies that she has decided to trust her sister and wait for the day when she can tell her what is going on. She tells him that her sister called her from a "waitress number" and that she told her not to worry because they are "family." The flashback ends with Hiroshi asking his mother what she means by "secret." His mother responds that she does not want her "secret" to get out of her, but that she is afraid that the "mugger" will "turn on the waterworks" and "kill" her. She then asks her mother what her secret is, and she replies that it is a matter of "life or death." She then tells her mother that she knows where her sister lives, and that if she goes looking for her, she will waste her resolve to become a novelist.