During the 2010 decade Casiopea 3rd resumed album releases, and both Casiopea 3rd and Inspirits held a joint concert as a result of having a common bandleader in Issei Noro. During the COVID-19 crisis, Issei Noro released a song titled A•RI•GA•TO (Appreciation), thanking all those on the frontlines. On February 10, 2022, Akira Jimbo announced he will be leaving Casiopea 3rd. His final appearance with Casiopea 3rd was during the April and May 2022 Billboard Tour. Casiopea-P4 (2022–present) On July 1, 2022, Issei Noro announced on the band's website that Yoshinori Imai will be the new drummer, and the band would rebrand to Casiopea-P4. The Recording Session for the first of Casiopea-P4 albums started, weeks after the rebrand. Offshoot bands Ottottrio In 1987, T-Square members Masahiro Andoh (guitarist) and Hiroyuki Noritake (drummer), Issei Noro and current KORENOS guitarist Hirokuni Korekata created a supergroup called Ottottrio. With a backing band composed by keyboardists Chizuko Yoshihiro and Shotoku Sasaji, and bassist Chiharu Mikuzuki, the group released 3 albums, 2 in 1988 and one called "Triptych" in 1998. In 1989, Ottottrio performed on the joint event "The Super Fusion", with all members of T-Square and Casiopea respectively, as well as Ottottrio's backing players. Casiopea vs. The Square After Ottottrio, the relationship between Casiopea and T-Square continued in 1993, when former T-Square percussionist Kiyohiko Senba played on one of the songs from Casiopea's album "Dramatic", and, a year later, the bands played together an arrangement of The Beatles "Get Back" on a Japanese Broadcast. In 1997, Casiopea, T-Square and Jimsaku played at Tokyo Jam, and in 2003 both groups played (with some of the players replaced), at the event Casiopea vs. The Square itself. More recently they still have somewhat of an alliance, seeing as Casiopea's former drummer Noriaki Kumagai and T-Square's former bassist Mitsuru Sutoh both in group TRIX, and T-Square Sax/EWI player Takeshi Itoh performance with Casiopea's former keyboardist Minoru Mukaiya in 2006. Synchronized DNA In 2005, Akira Jimbo and Hiroyuki Noritake created a Drum Duo called Synchronized DNA, who played in a tour with Casiopea, released as "Casiopea + Sync DNA: 5 Stars Live", and in their last album before hiatus, "Signal". Inspirits In 2008, Issei Noro created the band Issei Noro Inspirits, with Akira Jimbo, pianist Kent Ohgiya, keyboardist Ryo Hayashi and bassist Yuji Yajima as members. As of September 8, 2018, they have released five studio albums, one live