Keiko Onuki is Shogo Kawada's girlfriend from his previous school in Kobe; Keiko was in Shogo's class when the two were in a Battle Royale. In the novel, Shogo loses track of Keiko; Shogo believes that Keiko felt afraid of him. Shogo later discovered Keiko dead. In the manga, Shogo and Keiko meet. When Keiko seemingly points her gun towards Shogo, Shogo kills her; he later discovered that Keiko had aimed at a person behind him. (Source: Wikipedia)