A new key visual and main trailer have been unveiled for the upcoming fourth season of Mr. Osomatsu, which also confirmed its premiere in Japan on July 8, 2025.
It was also announced that Hitomi of the Japanese band Atarayo and the Osomatsu sextuplets cast will perform the ending theme song “Buddy.” Seiji Kameda composed and wrote the lyrics for the ending theme, and also handled the arrangement.
Meanwhile, the new trailer highlights the fourth season’s new opening theme song “Osomatsu-san no Bomba Sheeh!” performed by Japanese boy band DA PUMP. The group was announced to be performing the opening theme last week, which will be a Japanese language cover of an overseas song. Rapper m.c.A・T wrote the Japanese lyrics for the cover.
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— 「おそ松さん」公式アカウント (@osomatsu_PR) May 29, 2025
TVアニメ「 #おそ松さん 」
第4期OPテーマ担当アーティストが
DA PUMP に決定！
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⚡️ DA PUMP ISSAコメント
TVアニメ「おそ松さん」第4期オープニングテーマ「おそ松さんのボンバシェー！」をDA PUMPが担当する事になりました〜！… pic.twitter.com/v5G8rsBz1x
Yoshinori Odaka (storyboard artist and episode director in previous Mr. Osomatsu seasons, director of Mr. Villain’s Day Off) is directing the fourth season, with Shu Matsubara (returning) as series screenwriter and Eiji Abiko (reprising from Season 3) as character designer.
Meanwhile, the six returning main cast members from the previous seasons stars:
- • Takahiro Sakurai as Osomatsu
- • Yuichi Nakamura as Karamatsu
- • Hiroshi Kamiya as Choromatsu
- • Jun Fukuyama as Ichimatsu
- • Daisuke Ono as Jyushimatsu
- • Miyu Irino as Todomatsu
The newest Mr. Osomatsu season was announced last June and is the first entry in the series to be credited to Pierrot Films, Pierrot‘s rebranded second studio, who is handling the animation production.
The first season premiered from October 2015 to March 2016, the second season from October 2017 to March 2018, and the third from October 2020 to March 2021. The first two seasons were licensed for release in English by VIZ Media.
Mr. Osomatsu is inspired by the 1962 Osomatsu-kun gag manga series by the late Fujio Akatsuka, which revolves around the Matsuno sextuplets. The original manga ran in several Shogakukan magazines, with the first publication run lasting from April 15, 1962 to January 15, 1969.
The Osomatsu-kun manga previously inspired two anime adaptations, one of which was produced by Pierrot, and a 24-minute anime film in 1989. A live-action film was also released in Japan in 2022.
Aside from the TV anime, the new series has also inspired a 2019 Mr. Osomatsu anime film, two theatrical sixth anniversary projects in 2022 and 2023, and a non-Pierrot-produced short form web anime released in 2016. It also spawned several non-anime media releases such as a manga series by Masako Shitara, novels, and games.
Crunchyroll is streaming the Mr. Osomatsu TV anime series and feature film, describing the main premise of the series as:
Mr. Osomatsu is based off of the gag manga series Osomatsu-kun by Fujio Akatsuka, and ran from 1962 to 1969. The series features a set of sextuplets, the Matsuno brothers, with Osomatsu being the oldest brother and leader of the group.
