After analyzing Great Gozu's body, Kyoko's group discover that, along with Seiko, Sonosuke has also been killed with a knife to the chest, soon coming across a frightened Ruruka. Meanwhile, Makoto realises that the game's rules do not actually prohibit anyone from escaping, managing to get in contact with classmate, heir Byakuya Togami, to tell them about Monokuma's killing game...