On June 6, a special event celebrating the 10th anniversary of the TV anime Osomatsu-san, titled 10th ANNIVERSARY OSOMATSUSAN SPECIAL 6DAYS Opening Festival, was held at Marunouchi Piccadilly in Tokyo, bringing together 11 well-known voice actors.
Full Cast Appears on Stage
The stage lineup included Takahiro Sakurai (Osomatsu), Yuichi Nakamura (Karamatsu), Hiroshi Kamiya (Choromatsu), Jun Fukuyama (Ichimatsu), Daisuke Ono (Jyushimatsu), Miyu Irino (Todomatsu), Aya Endo (Totoko), Sachi Kokuryu (Chibita), Yoji Ueda (Dekapan), Nobuo Tobita (Dayon), and Momoko Saito (Hatabo).
Opening Night Highlights
The event was part of 10th ANNIVERSARY OSOMATSUSAN SPECIAL 6DAYS, which screened Episode 13 of Season 4, an episode that did not air in 2025, as well as Episode 3, “Raiu to Kakugari” (“Rain Shower and Crew Cut”), voted the No. 1 favorite episode of Season 4 by fans and staff. In addition to Marunouchi Piccadilly, events were also held at Shinjuku Piccadilly and Kawasaki Cinecitta in Kanagawa Prefecture.
The atmosphere opened on a lively note as the “six brothers” in mascot costumes appeared from the side of the stage and danced energetically to the Season 4 opening theme “Osomatsu-san no Bombashee!” by DA PUMP. They struck a pose together at the end of the song, drawing thunderous applause from fans.
After that, the six mascots continued roaming the stage, some sitting on the floor and others waving at the audience, to the point that host Tetsuya Yanagihara of the comedy duo America Zarigani could barely control them, making the entire theater laugh. It took a while before the voice actors could be invited onstage. Even as the 11 cast members appeared, the mascots remained mischievous, but fans welcomed everyone with warm applause. There was also an audience call-and-response using Jyushimatsu’s signature line, “Muscle Muscle! Hustle Hustle!”, led by Daisuke Ono, creating a lively sense of unity in the room.
Behind the Series Songs and Recording Stories
During the talk after the screening of Episode 13, Takahiro Sakurai frankly said, “I don’t know what I just watched,” making the other cast members smile onstage. Nakamura also joked about younger fans who might not recognize the sources of some parody scenes in the episode.
Another funny story came from the recording of “Katte ni Suruzan,” a duet by Yoji Ueda and Nobuo Tobita. Ueda joked that “the opening line is already the funniest part of the song,” and revealed that the director told him to “forget the character voice.” He responded, “Then isn’t that just regular Yoji Ueda singing?” Tobita said he received similar advice from writer Shu Matsubara, who also told him to forget the character first.
When the six brothers’ song “Neet Paradise” played in the theater, everyone on stage and in the audience laughed, especially when Hiroshi Kamiya’s part came on. Kamiya explained that he sang it according to the director’s instruction to sound “annoying,” and that it was not his own idea. Daisuke Ono, meanwhile, said he received no direction at all. “I finished in just two takes. I felt like they should have paid a little more attention to me,” he said with a laugh. Momoko Saito said in surprise, “I never thought they could look this cute and idol-like if they really tried.”
A 10-Year Memory Quiz
After the lively talk about Episode 13, the cast took part in a 10-year retrospective quiz, guessing lines from past interviews and identifying which episode preview certain lines came from. Some questions were difficult enough to stump everyone, such as Aya Endo being unable to remember the plot of a Totoko episode, while Jun Fukuyama was able to answer accurately from only small hints.
DENHAM Collaboration and Sakurai’s Farewell Message
Toward the end of the event, Miyu Irino, who was involved in the design process, introduced collaboration items with jeans brand DENHAM. Irino, Sakurai, and Fukuyama wore the collaboration jeans at the event and showed details such as pocket embroidery. Endo and Kokuryu wore the denim skirt and women’s jeans, and both commented on how soft and comfortable the fabric felt. Kokuryu asked whether the men’s styles looked just as good, and Irino replied, “There are men’s and women’s versions, but everyone can choose whichever they like.” He added that one of the brand’s appeals is that the jeans become more beautiful the longer they are worn, letting owners enjoy changes in the fabric over time. Preorders for the collaboration items will open through the Osomatsu-san fan club on June 8 at 10:00 a.m.
To close the event, Takahiro Sakurai spoke sincerely: “It has been a full 10 years. This is a long relationship, and it feels wonderful to gather again with all the cast members and fans.” He also told fans, “I truly love this work. Watching the retrospective videos reminded me of things I had forgotten and things I missed. I hope everyone goes back and watches from the beginning, including Season 4. Thank you very much for today!”
Source: natalie

