The Matsuno brothers try to adapt their show to contemporary times, with mixed results.

The Matsunos are invited to Hatobou's birthday part. Meanwhile, Iyami discovers that his buckteeth contain a rare metal.

Wanting to become the main protagonist of the franchise again, Iyami holds a bizarre kart race to determine who the protagonist of Osomatsu-san will be.

The Matsuno Brothers travel to the future and see they're going to get fat, greedy and finally beaten up by angry girls. They make an effort to change their ways, but they are destined to be beaten up.

Noticing Matsuzou acting strangely, the siblings discover that he is worried that there's not enough spark in his marriage with Matsuyo. Feeling he should return to a more innocent time, the boys give Matsuzou a masterlcass in being a virgin, albeit with no success. Matsuzou inevitably resorts to getting a love potion from Dekapan, but ultimately decides against using it, managing to sort things out with Matsuyo by himself.

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.

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.

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.

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.