After discovering the third island, Monokuma introduces everyone the new motive: the Despair Disease. Hajime is the first to witness its effects with Nagito, who apparently has the Liar Disease, Akane, who has the Coward Disease, Ibuki, who has the Guillible Disease, and you. So Mikan, Hajime and Fuyuhiko take the four of you to the hospital on the third island after Nagito collapsed to help you all, and Hajime decides to stay because he's worried for you since he knows you're his soulmate.