The official website for the live-action Mr. Osomatsu (Osomatsu-san) films announced on Friday that Snow Man idol group member Kōji Mukai is making a cameo in the second film, which opens on the same day. Mukai starred in the first film as the oldest of the Matsuno sextuplets, Osomatsu, in 2022, but in the new film, he now plays “former Osomatsu.”
Image via Mr. Osomatsu live-action films’ website
©映画「おそ松さん」製作委員会2026
The “former Osomatsu” is “a man who once lived as Osomatsu.” The new and former Osomatsus clash in the new film and “set off a dangerous chemical reaction!”
Mukai said that he was thrilled to receive the offer to appear in the new film, and that he became nostalgic even though he had just one day of shooting. He said that the new Osomatsu is closer to the original manga version that his own portrayal.
Image via Mr. Osomatsu live-action films’ website
©映画「おそ松さん」製作委員会2026
The new cast for the second film’s sextuplets are all performers from the Kansai region:
- Seiya Suezawa (Ae! Group) as Osomatsu (red shirt in picture right)
- Yoshinori Masakado (Ae! Group) as Karamatsu (blue shirt)
- Masaya Sano (Ae! Group) as Choromatsu (green shirt)
- Ken Kojima (Ae! Group) as Ichimatsu (purple shirt)
- Keita Richard Kusama as Jushimatsu (yellow shirt)
- Takuya Nishimura (Kansai Jr.) as Todomatsu (pink shirt)
In addition, four members from Starto Entertainment’s Kansai Junior make their film debuts as the “new Osomatsu brothers.” Atsushi Ito (Boys be group) plays the role of Shin Karamatsu, Kaito Noda as Shin Choromatsu, Taiga Watanabe as Shin Ichimatsu, and Shintarō Sumi (Boys be group) as Shin Jushimatsu.
Ae! Group also performs the film’s theme song “Dekoboko Life” (Rough Life).
Taisuke Kawamura (live-action Kuragehime, live-action Nodame Cantabile Saishū Gakushō) is directing the new film, and Takayuki Takuma is writing the screenplay.
The film opened in Japan on June 12. The website had announced on October 28 last year that the film had been delayed from its planned January 9 release due to various circumstances and after consulting with involved parties. Tokyo Metropolitan Police arrested Jushimatsu’s actor and now-former Japanese boy band Ae! Group member Keita Richard Kusama on October 4 on suspicion of indecent exposure.
Members of Snow Man, another popular idol group from Johnny & Associates (now known as Starto Entertainment), starred in the first live-action film. The first live-action film opened in March 2022.
The fourth season of the anime premiered on television in July 2025.
Sources: Mr. Osomatsu live-action films’ website, Comic Natalie


