Sayonara Zetsubou Sensei

When everyone's mind isn't functioning well after the New Year, Maria decides to tackle them in a manzai fashion. Nozumu Itoshiki explains that there are things other than the New Year that causes people to feel groggy such as jet lag. Ultimately, Maria decides to tackle the government of Japan arguing that Japan isn't paying enough attention on its national security matter during the peace time while the neighborhood countries are posing as threat. In the second part of the episode, Nozomu Itoshiki suddenly decides to inspect students by surprise. In order to help Nozomu to achieve his goal, Maria and Chiri starts taking photographs of vulnerable private moments of students. Nozomu's colleague, Jinroku, is the only one able to withstand the inspection 24 hours a day. Suddenly, Kafuka Fūra argues back that being a careless person can be a great appeal as it can draw sympathetic feeling from everyone. Chiri suddenly decides to take advantage of this trend by becoming a careless person on purpose, but it consequently puts many characters in grave danger.

When Nozomu Itoshiki tries take photograph of his nephew and Kafuka Fūra in the public swimming pool, he is accused of being a spy by another woman. Nozomu blames the society, where everyone, including those who do not have any malicious intent, is suspected of being spy. Suddenly, Kafuka gives him a secret mission and Nozomu has to escapes from the greater suspicion by finding a good place to isolate himself. At the end, Kafuka devises a plan of 'positive counter intelligence' to help him out by leaking unreliable rumors such as urban legends to confuse everyone in the society. In the second part of the episode, Nozomu claims that pretentious side of everyone is ultimately exposed in May. At the end, many of Nozomu's students' hidden secrets are exposed, though some of them are merely his imagination. In the third part of the episode, many things in the world are not divided exactly half and half despite their claim. To correct such mistakes in the world, Chiri Kitsu enforce the ratio of everything into exactly 50/50 ratio, which produces various results at the end.

Nozomu Itoshiki hands out an application for his pension in a government office, but an employee makes fun of Nozomu's name. Nozomu is sick of hearing the same thing about himself over a million times and he sympathizes with other people, who have experienced a similar situation for countless times in their life. Meanwhile, Harumi Fujiyoshi realizes that she is an extreme minority as no one seems to agree with her view. The second part of the episode shows a Zetsubō channel featuring a number of television programs such as audience survey, music show, magical girl anime, cooking show, etc. In the third part of the episode, Nozomu is kicked out of a café, because a Jyuken student is constantly irritated by him. The café manager kindly asks Nozomu to forgive him, because it is generally believed that exam-preparing students should be treated with the utmost care. Though Nozomu can't quite understand this kind of expectation in the Japanese society, he nevertheless tries to take advantage of this trend by becoming an exam-preparing student himself. Eventually, he happens to pass every certificate exams in the world except for one: an exam that tests whether a person is ready enough to commit suicide. However, he fails the exam and thus becomes not worthy enough to live nor worthy enough to die. The third part of the episode is shown using various animation techniques.

It's time to hand out grades, but Nozomu Itoshiki hands out completely censored report cards to his students, because he understands that majority of students do not want to be notified of their grades. He argues that people should have right to choose to be 'uninformed' of undesirable information, since they have right to be informed of desirable information. Ultimately, he tries to escape civilization to become 'free' of all the notifications in the world, but he is still in despair as nature are also trying to communicate with him. Meanwhile, Kafuka Fūra is admiring the all-knowing housewife in the neighborhood. In the second part of the episode, Nozomu Itoshiki and his nephew, Majiru, fall asleep together and have a dream where everyone's personality is reversed. The students in his dream realize that they will disappear when Nozomu wakes up, so they try to put him in an eternal sleep by murdering him in his dream. In the third part of the episode, Nozomu and his students discuss various things that are kept secret or unknown from their parents. During this section, the characters are voiced by numerous random voice actors (with most of them from the show itself), and are changed frequently.

Nozomu Itoshiki and his students enjoy the festival of Tanabata and talk about instances where people pay more attention to the trivial details of many objects rather than the main subjects. In the middle of their conversation, which Ikkyū-san later joins, the alien race El Niño suddenly invades Japan with their mecha army. Fortunately, Chiri digs up an ancient mask and activates its hidden power to defeat the alien force. The aliens admits their mistake of paying attention to trivial aspects of Nozomu's students rather than the progress of their invasion. At the end, Nozomu and Ikkyū-san do not remember how Japan was saved from the alien invasion, as they were paying attention to trivial details of the battle scene. In the second part of the episode, Jun Kudō is reading books in the school library, while Nozumu is worried about Jun's desire to read everything in the world, which could eventually include Nozomu's own embarrassing mind. When Nozomu's other students visit the school library, Jun tells heart-warming stories that move every one of them to tears. Nozomu feels even more certain of Jun's ability to read people's minds, so he puts himself in a freezing room full of penguins to prevent Jun from reading the conclusion of the episode. The third part of the episode shows what happened between Nozomu's nephew, Majiru Itoshiki, and Kiri Komori while the alien invasion of the 'A Painter by the Roadside' episode was undergoing outside the house.

Nozomu Itoshiki and his students enjoy the festival of Tanabata and talk about instances where people pay more attention to the trivial details of many objects rather than the main subjects. In the middle of their conversation, which Ikkyū-san later joins, the alien race El Niño suddenly invades Japan with their mecha army. Fortunately, Chiri digs up an ancient mask and activates its hidden power to defeat the alien force. The aliens admits their mistake of paying attention to trivial aspects of Nozomu's students rather than the progress of their invasion. At the end, Nozomu and Ikkyū-san do not remember how Japan was saved from the alien invasion, as they were paying attention to trivial details of the battle scene. In the second part of the episode, Jun Kudō is reading books in the school library, while Nozumu is worried about Jun's desire to read everything in the world, which could eventually include Nozomu's own embarrassing mind. When Nozomu's other students visit the school library, Jun tells heart-warming stories that move every one of them to tears. Nozomu feels even more certain of Jun's ability to read people's minds, so he puts himself in a freezing room full of penguins to prevent Jun from reading the conclusion of the episode. The third part of the episode shows what happened between Nozomu's nephew, Majiru Itoshiki, and Kiri Komori while the alien invasion of the 'A Painter by the Roadside' episode was undergoing outside the house.

Harumi Fujiyoshi is listening to a Zetsubō Sensei radio show at home while working on her yaoi dōjinshi. The radio show is actually derived from a chapter of the Zetsubō Sensei manga, which portrays Japanese people's indifference to their ages and introduces a new character, Manami Ōkusa, who is a married high school student. In the second part of the episode, Nozomu criticizes the society where individuals are compelled to serve their 'duties' to meet other people's expectations. These 'duties' are often very superfluous and trivial. However, Kafuka points out the irony that Nozomu himself is a part of such a society, as the girls around him are expected to serve their various 'duties' to take care of their teacher. In the third part of the episode, Nozomu is in despair about society, where serious matters are often taken too lightly. Several of Nozumu's students provide their experiences of such a trend. After Rin Itoshiki makes an appearance as one of Nozomu's new students, Nozomu and his students decide to reverse the trend by treating various trivial matters with serious attitudes, which eventually becomes an addicting habit for everyone.

The first part of this episode is supposed to follow this storyline from a chapter of the Zetsubō Sensei manga. Perry has come to the school on the anniversary of the school's founding. He is an American Commodore who known for opening up Japanese ports to foreign trade (in Japanese, the phrase "opening the school" (開校?) is pronounced the same as "opening the ports" (開港?)). After he opens up various things in the school, he tries to open up Nozomu Itoshiki's mind. Suddenly, Nozomu releases a mysterious wave that reveals the dark side of the world, which is full of despair. Finally, Perry learns the lesson that he shouldn't try to open up everything in the world. However, all the characters speak unintelligible gibberish, and the subtitles suggest that Perry is Son Goku looking for the Dragon Balls and that Nozomu is an alien bent on stopping him. In the next part of the episode, Nozomu is complaining about the over-decoration of various things in Japanese society. However, Kafuka Fūra denies it, saying that it is just a trend among stylish elites. In the next part, Nozomu meets his old time friend Ikkyū-san, who likes old things. They discuss together how old things are often ignored in modern Japan. Ultimately, he wants to obtain a former-surname by marrying Nozomu's sister Rin. Rin tries to escape from Ikkyū by calling her butler, but he ends up persuading Ikkyū-san to marry her. However, Kafuka manages to find out at the end that Nozomu and Ikkyū are not old friends, but rather one-day friends during the first day of school.

Nozomu Itoshiki, a direct marketing businessman, is chased by a mysterious religious group called Hamasho. At one point, he is caught and his body is modified like a mole cricket. After his long adventure, he is discovered by Kafuka and he then becomes a high school teacher. Students in the class start calling him "Left-wing Guerrilla" (apparently in lieu of "Pink Supervisor"), making him want to die again. Right before he jumps off a cliff, Kafuka suggests he "mock marry" a girl of the Holy Nosebleed Empire. A card reveals that the entire segment is a gag based on a summary from the jacket of the manga's first volume. In the second segment, Nami Hitō, who has been missing classes, finally decides to attend her school as no one really seems to notice her absence. Unfortunately, she does not get much attention from her classmates as the high school is full of extraordinary characters. At the end of the episode, most of the major characters are introduced and Nami is labeled as the 'ordinary girl' in the school.

This episode begins with Usui Kagerou lamenting about how he never gets noticed by anyone, when he nearly gets run over by a truck who does not notice him. He runs into Nozomu in the shadows, who begins to talk about how some people are destined to be overshadowed by others, no matter how hard they work. The second part of the episode has the class undergo criticism training. Usui continues to be ignored until a divine wind blows away his hair, revealing his bald head and allowing everyone in the class to see him. He fears that people in the class will begin mocking him, but Kafuka suggests that Chie insults him instead, which he seems to enjoy.

This episode begins with Fujiyoshi bumping into Nozomu while she is on her way to make copies of her doujinshi. Through a misunderstanding, Nozomu ends up going to Comiket to sell his doujin literature with mixed results. At Comiket, Chiri reads Fujiyoshi's yaoi doujinshi. On the way back from Comiket, they meet Kafuka, who talks Chiri and Fujiyoshi into drawing more manga that strictly adheres to the above mentioned format. The second half of the episode involves the girls at a matsuri, where overzealous festival-goers begin piling random objects and people on portable shrines and dancing and parading around with them.

Kafuka comes down with a cold during the summer and has to go see the doctor, Mikoto Itoshiki, who happens to be Nozomu's brother. Later, Chiri and Kafuka find out from Mikoto that Nozomu has gone back to his hometown in Kuraizawa for an arranged marriage. One way or another, the girls somehow all end up arriving at Kuraizawa, where they are taken to the Itoshiki residence by Tokita. Here they find out that the Itoshiki tradition for arranged marriages simply involves both parties exchanging eye contact. The rest of the episode involves Nozomu and his attempts to avoid eye contact with the girls and various other people/objects.

On physical examination day, many of the girls are feeling stress about their weight, measurements and fitness. Nozumu distracts them by deciding to judge the "social worth" of students so that they will know whether they are living "above their station." Kitsu seizes on this idea, scolding everyone who possesses any luxuries, appalling Nozumu to the point where he decides to go on a hedonistic binge before killing himself. In the second half he encounters some of his students at a hot spring and is frightened to learn the spring has the power to remove their "toxicity" giving them well-adjusted personalities.

Chie dispatches Nozomu to investigate rumors that the invariably injured Abiru Kobushi is suffering from domestic violence. He pursues Abiru's father while he shops, causing him a great deal of inconvenience, before discovering Abiru's obsession with pulling the tails of dangerous animals. The latter half of the episode concerns Meru Otonashi, who is silent and shy in person, but remarkably abusive via text-messaging, her only means of communication.

This episode is a pastiche of parodies about foreigners and Japanese attitudes concerning them. A foreign student named Kaere Kimura transfers into the class. Kimura is a blonde girl with multiple personality disorder stemming from cultural identity confusion. Nozumu prevents her from committing suicide but sees her underwear and is sued. While Nozomu is absent from school Chiri investigates his students and discovers that Maria is an illegal immigrant.

After confiding in his latest despairs to Ms. Arai, she asks Nozomu to visit one of his students who hasn't shown up to school — Kiri Komori, a hikikomori. In the end Kiri goes to school but decides to be a hikimori there. The next day, Nozomu notes that another of his students, Matoi Tsunetsuki, didn't show up that day. Ms. Arai brings Nozomu to the counseling room, where she explains Matoi's obsessive-stalker tendencies to Nozomu. That night, he attempts to dissuade her from bothering her last boyfriend; however, his strategy backfires on him. This turns him into Matoi's latest object of affection.

Kafuka Fuura is cheerily walking to school one April morning when she suddenly spots a man trying to hang himself in a fit of despair. Kafuka manages to use her weight to snap the rope, thus saving his life. Nozomu Itoshiki, the man, eventually cannot take anymore of the girl's ridiculous ramblings, and runs off to school to start homeroom at the beginning of a new school year. When Nozomu walks in the door, he finds Kafuka is one of his students.

The gang encounter several groups of protestors, who protest about things, but end up vaccilating over certain things. Nozomu soons winds up in the same scenario when he comments on the earliness of his gag. Maria shows him a tepid vaccilation, where her cuteness gets her out of several troubles, including extinguishing the Olympic Torch. In the second part, the gang discuss matters where you're compelled to say something is interesting or funny. Matoi decides they should use these tactics to get more laughs from the low minded viewers by using complicated word gags. However, they get attacked by Chiri when she doesn't get the desired response from her dialogue. The third part introduces us to Tane Kitsu, Chiri's older sister who, as a polar opposite to Chiri, constantly makes everything messy. Harumi explains to Nozomu that Tane became messy to stop Chiri from cleaning a goldfish with shampoo when they were little. Nozomu uses this knowledge to control Chiri, whilst Tane falls for him.

In a Book of Folktales, it shows how Nozomu, first a positive, normal person as a student, is forced to become the negative man he is today.

Nozomu is paying a visit to Chiri's house after going through various scenes, but his home visit abruptly ends when he reaches Chiri's house. Chiri argues that Nozomu's visit was pointless, but Nozomu points out that most Japanese people take the process more seriously rather than its result. As a typical shōnen manga puts emphasis on the character's development throughout the story, Nozomu asks his students to appeal the audience by showing off development of their immaturity. In the second part of the episode, a warning of earthquake disaster is published by the Ministry of Prediction, which makes every characters except Chiri very lazy as they believe they are not going to make appearance in the magazine. Meanwhile Nozomu points that many Japanese put efforts into various activities despite being aware there won't be any reward for their action. A number of Nozomu's students ends up doing improper conducts as they don't expect themselves to appear in front of the audience. In the third part of the episode, the students are worrying about the dropping interest of book-reading among students. Nozomu thinks that many books should change their titles so that they accurately reflect the content of the book as many books betray the readers' trusts by having inaccurate title. Thus, Nozomu asks Kino and Kudo to give more appropriate names for various books by holding a book-titling competition.

Valentine's Day has arrived and Nozomu is rather popular. Wondering if this is a honey trap, appealing to a man's desires to obtain secret information, he is introduced to an elite group of otakus, whose disinterest in real women allows them to carry top secret information without falling into the honey trap. Nozomu then ponders about the violent nature of unaired battles, before Chiri discovers his unaired training. Later, Nozomu goes to a halloween party only to find his ideals about Halloween are much different from current ideals, and dwells upon things not being like the original.

A special summary episode of the second season of Sayonara Zetsubou Sensei, focusing on the girls that were not introduced in the first Zetsubou Shoujo Senshuu: Otonashi Meru, Fujiyoshi Harumi, Kaga Ai and Mitama Mayo.

A special summary episode of the first season of Sayonara Zetsubou Sensei, focusing on seven of the girls: Komori Kiri, Matoi Tsunetsuki, Kobushi Abiru, Kimura Kaere, Kitsu Chiri, Sekiuchi "Maria" Tarou and Hitou Nami.