Kana Ushiro

Оригінальне ім’я: 宇白可奈

Ushiro's little sister; initially the audience is led to believe that she is the only one of the children who does not sign the contract. because Ushiro, who constantly abuses her, does not want her to. When they sign the contract, they are not aware of their inevitable fate and they are told that they would be "testing a game." (Source: Wikipedia)