Nozomu Itoshiki is a high school teacher so pessimistic that even the smallest of misfortunes can send him into a pit of raging despair; some of these "catastrophes" even lead to suicide attempts. Sayonara Zetsubou Sensei is a satirical slice-of-life comedy set in the modern day, covering various aspects of Japanese life and culture through Nozomu and his interactions with his students: Kiri Komori, a recluse who refuses to leave the school; Abiru Kobushi, an enigma who frequently arrives to class with severe and mysterious injuries; the hyper-optimistic Kafuuka Fuura, Nozomu's polar opposite; and several other unusual girls, all of whom are just as eccentric as their teacher. [Written by MAL Rewrite]

Frazzle-haired middle schooler Inari Fushimi is less than average; she's painfully shy and horribly clumsy, but despite all this, she is undeniably kind. Running about the winding streets of her hometown, she takes a shortcut through the local shrine and stumbles upon a small fox pup in a river. After rescuing him, she continues on, but from this moment on, her life takes a drastic turn. Grateful for rescuing the pup, the shrine goddess Uka-no-Mitama-no-Kami, "Uka-sama," grants Inari a fragment of her power. Now, Inari has the ability to transform into anyone by shouting the magical phrase "Inari, konkon." Could this power also grant her the courage to convey her feelings to her crush, Kouji Tanbabashi? With her new heavenly ability and the fox spirit Kon, Inari forms a sincere friendship with Uka-sama, encounters more of the supernatural world, and learns that true love knows no bounds. [Written by MAL Rewrite]

Graduation looms for the founding members of the Light Music Club. With only a few precious weeks of school left, the girls decide to make the most of it and plan a trip abroad. Hawaii, New York, Dubai—many destinations are suggested, but after a little help from the club's precious pet turtle, Ton-chan, London is chosen as the host of their next misadventure! Yui Hirasawa, Mio Akiyama, Tsumugi Kotobuki, Ritsu Tainaka, and Azusa Nakano will visit famous landmarks, perform live music for Londoners, and eat all sorts of delicious food, all while stumbling clumsily from place to place. But the fun won't last forever, as heartfelt songs and goodbyes will be made as their high school days together come to a close. One thing is for certain though: the undeniable friendships these girls have formed is something that will carry on long after the final scene rolls.

Upon hearing news that his mother was on verge of death, Haru Kaidou—the eldest son of the family—flies all the way to Canada. The moment he arrives, he learns that not only did his mother fool him, but he is also supposed to take care of his adoptive brother, Ren Kaidou, an antisocial kid who feels more comfortable around dogs than people. Due to his new brother's distrustful nature, Haru initially has a hard time reaching out to Ren but their relationship eventually grows. He makes a promise to Ren: they will live together in Japan after Haru graduates from high school. However, due to an unfortunate accident, Haru loses all memories of the summer they spent together, including the promise he made. Five years later, expecting Haru to keep his promise, Ren arrives in Tokyo; but to Haru, Ren is just a random boy claiming to be his brother. [Written by MAL Rewrite]