Iyami crashes a plane into the Matsuno home, killing the six brothers and sending them to hell.

Matsuzou becomes hospitalized, leading the brothers to seriously think about their lives and get proper jobs to support their family. As Osomatsu starts to find this new life boring, Totoko encourages him to think for himself.

Dayon meets another Dayon, and Iyami ponders is self-worth.

Hatabou treats everyone to a trip to Hawaii, but you probably realize that's not going to happen.

The brothers get rowdy while getting drunk at a restaurant. Unemployed office lady Totomi ends up taking a job at a strange establishment that offers some peculiar services. After being visited by a salesman, Matsuyo contemplates sending off one of her sons to a NEET correctional facility, asking Choromatsu to help her decide which one to send away.

Yet another collection of random skits. Chibita tries selling some sextuplet meats buns, Choromatsu files his taxes, Osomatsu accuses his brothers of stealing his wallet, a fierce wave of pollen hits town, Totoko tries to escape a creepy maze, Jyushimatsu becomes a raccoon, Todomatsu tries doing something crazy, kindergartners visit a bread factory, the Proper-Rangers prepare to set off, and Osomatsu takes part in a skeleton event.

After Dekapan becomes president, his secretary Todomatsu tries to keep him from pressing the Big Red Button. Iyami attempts to pull off a sham ventriloquism scheme by having Chibita and Hatabou act as his puppets. On Valentine's Day, the brothers try in vain to get some Valentine's chocolate from someone.

Iyami encounters a blind little girl and does what he can to make her dreams come true.

Ichimatsu becomes paranoid when lucky things happen to him all day, so he and Jyushimatsu try to punish themselves to balance things out. A lovey-dovey couple go to a hot spring inn that's haunted by a zashiki-warashi named Osoma.

A group of aliens pursue the legendary space pirate, Shazarr. Displeased with Chibita's oden, Matsuzou serves up his own brand of oden, only for noone to show up. Later, the sextuplets become enamored by their new neighbor, Kinko Inuyama, prompting jealousy from Totoko when they go on a date with Kinko instead of her.

The brothers struggle to remove the lid off of a particularly stubborn jar. Karamatsu runs his own taxi service, proving to have no idea what he is doing when he picks up an office lady. Finally, Totty holds a quiz for his brothers, containing several questions without right answers.

Sanematsu wakes up in Osomatsu's world as the seventh Matsuno brother. After spending several weeks of happiness with the siblings, Sanematsu eventually realises it was all a delusion he had been experiencing after ending up in a car accident. Jyushimatsu, Iyami, and Hatabou go on an expedition to find a Super Mongolian Death Worm. Choromatsu changes up his image by dying his hair brown, making it hard for his brothers to tell him that it's doesn't actually make him look cool.

A series of end-of-year skits. Osomatsu and Choromatsu try to do one thing that could make them say they had a good year. Ichimatsu gets persuaded to take part in a lottery, Dekapan and Dayon pound mochi together, Hatobou gets pestered by some greedy Jizou statues, Choromatsu sends some untruthful New Years' cards. Todomatsu is fired from the Matsuno family and is forced to try out for a reserve team.

Jyushimatsu befriends a young boy named Eitarou but gets called in by Eitarou's mother when he starts imitating him. Contrary to Jyushimatsu's fears, however, she asks him to teach Eitarou jokes so he can make friends at school. Later, Dayon steals Dekapan's underwear, forcing him to give chase all over the city while butt naked.

Already angered over the siblings gambling instead of paying off their oden tab, Chibita vows revenge on them after they pluck out his one-and-only hair. That night, Chibita begins taking out the siblings on by one, shaving all of their hair and stuffing oden in their faces.

Karamatsu just wants to be loved by his brothers.

Ichimatsu just wants to get some sleep and Iyami is a game master.

Jyushimatsu trains to become a dolphin... No, really.

In a parody of Romance of the Three Kingdoms, Emperor Osomatsu and a group of bizarre generals attempt to take over the country. Meanwhile, in the real world, Osomatsu joins Todomatsu at a mixer, struggling to keep his perverted instincts in check.

The sextuplets take care of Iyami but soon regret it. Later, Hatabou wants a friend.

A series of summer gags.

The Matsuno brothers try to aid their father in reviving the spark in his relationship with his wife.

Choromatsu and Ichimatsu struggle to make conversation with each other. Later, Totoko takes part in an eating contest but keeps getting distracted by the brothers.

The siblings try their hand at internet streaming. Later, Iyami uses an experimental detergent to keep his suit clean, but it's drunk by the siblings and makes them invisible.

Learning about Mr. Osomatsu's second season, the sextuplets of the past decide to see how they've turned out in the future.