The official website for the Mr. Osomatsu anime franchise confirmed the second theatrical OVA, Osomatsu-san: Tamashii no Takoyaki Party to Densetsu no Otomari-kai (Mr. Osomatsu: The Soul’s Takoyaki Party and the Legendary Sleepover Party), will get a limited-time theatrical screening in Japan from July 21, 2023 to celebrate the series’ sixth anniversary.
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.