After discovering the truth of her brother's disappearance, Shiro realizes that Sora is having a highly-staked game of Othello against Kurami, each betting their own existence and memories. With Sora in a dire position and unable to continue the game, Shiro assumes his place according to the game's rules and wins. With this, the siblings earn both the allegiance and trust of Kurami and her Elf partner Fil.