The unusual Class 77-B at Hope's Peak Academy gets a new homeroom teacher, Chisa Yukizome, a former student known as the Super High School-Level Housekeeper. Full of energy and skill, she works to heal the broken relationships among her varied students, who include a princess, a nurse, a yakuza member, and an incredibly lucky person. Trusting in the strength of hope, she tries to steer them through their disputes.
At the same time, Hajime Hinata, a Reserve Course student who feels he lacks any special ability, meets Chiaki Nanami, the Super High School-Level Gamer. Through their time together, she gives him a new way of looking at life. But without Hajime's knowledge, the school's administration is engineering a dark scheme involving him that could bring down Hope's Peak and devastate the world.
Zetsubou-hen follows the daily life at the famous academy while dark forces work in the background. As despair slowly takes over hope, those responsible for the Biggest, Most Awful, Most Tragic Event in Human History start their plan, marking the start of the end.