Get ready for more NEET antics! The fourth season of Mr. Osomatsu is officially hitting Japanese television screens on July 8, 2025. A brand new promo video has dropped, revealing the opening and ending theme songs that will accompany the Matsuno sextuplets’ chaotic return. Here’s everything you need to know.
The Matsuno Brothers Are Back!
Mr. Osomatsu (Osomatsu-san) is a comedy anime television series produced by Pierrot Films, based on Fujio Akatsuka’s 1962 manga series, Osomatsu-kun. The original manga centered on the Matsuno sextuplets – Osomatsu, Karamatsu, Choromatsu, Ichimatsu, Jyushimatsu, and Todomatsu – as mischievous ten-year-olds. Mr. Osomatsu reimagines the brothers as adults: lazy, unemployed, and perpetually single NEETs (Not in Education, Employment, or Training).
Celebrating Akatsuka’s eightieth birthday, Mr. Osomatsu features more adult-oriented humor compared to the original series, quickly gaining popularity for its surreal comedy, slice-of-life moments, and parodies.
A Quick Look Back
The first season of Mr. Osomatsu aired in Japan from October 2015 to March 2016. A second season followed from October 2017 to March 2018, and a third season aired from October 2020 to March 2021. The franchise also includes the Eiga no Osomatsu-san film, which debuted in 2019, as well as various anime shorts, two anime films released in 2022 and 2023, and even a live-action film.
What to Expect in Season 4
While specific plot details for the fourth season are still under wraps, fans can anticipate more of the same wild and unpredictable humor that has made Mr. Osomatsu a hit. Expect the sextuplets to stumble through absurd situations, engage in ridiculous arguments, and generally wreak havoc on their own lives and the lives of those around them.
The series typically parodies popular anime tropes and cultural trends, so keep an eye out for clever references and meta-commentary. The core appeal of Mr. Osomatsu lies in its relatable portrayal of the struggles of adulthood, albeit through a highly exaggerated and comedic lens. The brothers may be NEETs, but their individual personalities and unique quirks make them endearing (in their own strange way).
Theme Songs Revealed!
The promo video for Mr. Osomatsu Season 4 offers a sneak peek at the theme songs that will be featured in the upcoming season.
Opening Theme: “Osomatsu-san no Bomba Sheeh!” by DA PUMP
The opening theme song is titled “Osomatsu-san no Bomba Sheeh!” and is performed by the Japanese boy band DA PUMP. The song is a Japanese-language cover of an overseas song. Rapper m.c.A.T., who produced many of DA PUMP’s hit songs early in their career, wrote the Japanese lyrics for the cover.
DA PUMP is a six-member group known for their energetic performances and catchy tunes. In a promotional image, the members of DA PUMP are even cosplaying as Iyami, striking his iconic “Sheeh!” pose.
Ending Theme: “Buddy” by Atarayo and the Osomatsu Sextuplets
The ending theme song is “Buddy,” performed by Atarayo and the Osomatsu sextuplets themselves. Seiji Kameda composed, arranged, and wrote the lyrics for the ending theme song.
Production Details
Yoshinori Odaka, who directed the Osomatsu-san ~Hipipo-Zoku to Kagayaku Kajitsu~ film and served as an episode director for the first and third seasons, is directing the fourth season at Pierrot Films. Shū Matsubara is once again in charge of series scripts, and Eiji Abiko is returning as the character designer.
The Cast Returns
Fans will be happy to know that the original voice cast is returning to reprise their roles as the Matsuno sextuplets:
- Takahiro Sakurai as Osomatsu Matsuno
- Yūichi Nakamura as Karamatsu Matsuno
- Hiroshi Kamiya as Choromatsu Matsuno
- Jun Fukuyama as Ichimatsu Matsuno
- Daisuke Ono as Jyushimatsu Matsuno
- Miyu Irino as Todomatsu Matsuno
Where to Watch
Mr. Osomatsu Season 4 will premiere on July 8, 2025, at 12:00 a.m. JST (effectively, July 9) on TV Tokyo, TV Osaka, TV Aichi, TV Setouchi, TV Hokkaido, and TVQ Kyushu, before airing on other networks.
Crunchyroll currently streams the previous three seasons of Mr. Osomatsu, as well as the Mr. Osomatsu movie.
Meet the Sextuplets
Here’s a quick rundown of each of the Matsuno brothers:
- Osomatsu: The eldest and self-proclaimed leader. He’s an avid gambler who enjoys pachinko and betting on horses. He’s typically dressed in red.
- Karamatsu: The second-born, who believes himself to be cool and popular (though he’s often delusional). He’s known for his flamboyant fashion sense and his tendency to insert English words into his sentences.
- Choromatsu: The most “responsible” of the brothers, but also a hardcore otaku with a love for idols. He often tries to be the voice of reason, but his efforts usually fail.
- Ichimatsu: A cynical and introverted brother who prefers the company of cats. He’s often seen as gloomy and detached.
- Jyushimatsu: An energetic and unpredictable brother with a love for baseball. He’s known for his bizarre antics and generally nonsensical behavior.
- Todomatsu: The youngest brother, who is often portrayed as cunning and manipulative. He’s the most social media-savvy of the sextuplets and tries to maintain a “normal” image.
A Comedy for the Ages
Mr. Osomatsu continues to resonate with audiences due to its unique blend of humor, relatable characters, and willingness to push boundaries. Whether you’re a long-time fan or new to the series, Season 4 promises to deliver another dose of the Matsuno brothers’ signature brand of chaos.
