When Mizuho's name is called, she g

When Mizuho's name is called, she gets up and as she is about to leave, Kaori runs up to her, telling her that they were still friends which Mizuho tearfully agrees before exiting.

Later Mizuho and Kaori manage to meetup with each other and ironically end up killing one another (obviously indicated by the pickaxe planted in Mizuho's chest and the knife in Kaori's side). The life preserver that lies between them offers evidence that this was what caused them to fight although it is not stated.