Via the Biggest, Worst Incident in the History of Mankind, SHSL Zetsubou has driven the former world to destruction. In order to save this despair-soaked world, the Future Foundation was formed.

Naegi and his fellow 78th Class classmates, having defeated Enoshima Junko, have joined the Future Foundation. There they are working to rebuild the world, but Naegi has been charged with the crime of treason for protecting the Remnants of Despair. Everyone gathered for Naegi’s punishment has been trapped by Monokuma and thrust into the “Final Killing Game”. Everyone is fitted with a strange bracelet that releases a sleeping potion at a fixed time. While asleep, the traitor in their midst kills a Future Foundation member.

To survive, they’ll have to ferret out the traitor and stop the killing.

The class trial rules do not apply to this killing game. Naegi and the others have been driven into a desperate kill or be killed situation.

The tale of hope and the despair that kills hope begins now.

