In the Japanese version Hikora calls his sister quotImotoquot which is the Japanese word for quotyounger sisterquot. So it is guessed Sorincha is Hikoras younger sister. Sorincha went to play the game of Otokoyo and did not return. She appears to be possessed by a demon since at the end of the movie her mask changes to that of a demons... the quotFifth Demonquot in the city. It is possessed that the night before she was the last kid left and didnt get caught and the possessed mask was put on her making her quotitquot for the next game. It is unknown what happened to Sorincha at the end of the game she is not shown at the end.