Monokuma has announced a new rule regarding the class trials. The Blackened or someone else will have the ability to corrupt a random student which, alongside the blackened, will become a threat to the entire group. The corrupted students will suffer an..."interesting change" and during the class trial its their decision to pick which one is the original demon to stop their influence...and which one is the killer after that is decided. Then both will get punished. The demon only can get punished if their true demonic identity (not human identity) is revealed and can still persistently linger outside of class trials with the penalty of a student getting corrupted by them. If the demon doesn't get out of the victim's body when the truth of their identity is revealed and votes are cast on the blackened...the victim will get executed alongside them. One student must find the truth of the school to become an exorcist. Also the demon can't be murdered otherwise the potential blackened gets possessed by them...but the demon usually is impervious to attacks.

The casts from Danganronpa 1, 2 and V3 are invited to this killing game.