Hope's Peak Academy's unconventional class 77-B is about to have an even more eccentric addition: Chisa Yukizome, an alumna with the title of Super High School-Level Housekeeper—and their new homeroom teacher. Cheerful, passionate, and capable, Chisa immediately sets about correcting the students' problematic behavior and strengthening their relationships. It may not be easy dealing with diverse pupils ranging from princesses and nurses to yakuza and impossibly lucky students, but anything is possible with the power of hope. Meanwhile, Hajime Hinata, an unremarkable boy from the school's Reserve Course, longs for a talent. One day, he has an unexpected meeting with class 77-B's Super High School-Level Gamer Chiaki Nanami, who presents to him a new, hope-filled outlook on life. However, unbeknownst to him, the school's upper echelon is about to execute a sinister project centered around Hajime that will bring Hope's Peak—and the rest of the world—to its knees. Zetsubou-hen chronicles the daily lives carried out at the talent-cultivating academy, and the darkness that lurks beneath. As despair slowly infects hope, plans are put into motion to start the Biggest, Most Awful, Most Tragic Event in Human History, and the end begins.

Uruno, a useless wolf, is on the road searching for a new place to call home. He soon comes upon a whole forest full of useless animals—that is, animals that don't live up to their species' usual character. After a short fight with the smoking, bad-tempered rabbit, Usahara, Uruno decides that he wants to move on... but changes his mind upon meeting Chiiko, a clumsy cheetah girl. It's love at first sight for Uruno, and after deciding to stay for her, he continues to hope that even though he's a good-for-nothing, he'll win her over someday. That is, if living with the other strange residents of the forest—including the aforementioned smoking rabbit, a sake-drinking unicorn, a near-sighted eagle, an orca that cannot swim, and a shy pegasus—doesn't get to him first.

The Tsunashi couple is as lively and offbeat as ever. Hardcore otaku shut-in Hajime and workaholic office lady Kaoru still get themselves into hilarious situations thanks to both their own eccentric natures and the bizarre group of friends surrounding them. After learning about Kaoru's pregnancy, Hajime works harder than ever to become a good husband and a worthy father. Meanwhile, Kaoru reflects on their relationship and remembers all of the trials and tribulations that brought them closer. The two of them continue to put their best foot forward in their lives and their marriage—all for the sake of long-lasting, selfless love.

Kiri Haimura has an obsession with beautiful hair—specifically, cutting it. This bizarre trait is what leads him to seek out a rumored long-haired ghost who lives in an abandoned house on a hill. However, he finds not a ghost, but a beautiful girl with long flowing hair named Iwai Mushanokouji, the Hair Queen, whose hair cannot be cut due to a family curse. Iwai explains that there is a death game surrounding her, and that if she is killed by a cursed object, aptly named a Killing Good, the wielder gets their wish granted. After protecting Iwai from Authors—Killing Goods users—he learns there is in fact a Killing Good passed down in his own family: a pair of scissors used by his ancestor to commit murders. Naming the scissors The Severing Crime Edge, he finds that he is able to cut Iwai's cursed hair with them, setting her free to live a normal life. However, many Authors seek to kill the Hair Queen, and Kiri will have to protect her in this lethal game of fate.