Yoshinori Sunahara and Leo Imai played Fuji Rock Festival ‘21 as a special one-off lineup, with Kenichi Shirane (GREAT3) on drums and Seiichi Nagai (Soutaiseiriron) on guitar. The four-piece subsequently changed their name to TESTSET. In 2022, they released their first EP ‘EP1 TSTST’ and played a series of shows and festivals, including SONIC MANIA and ASAGIRI JAM. They release their first album ‘1STST’ on July 12th, 2023, and will play the White Stage at FUJI ROCK FESTIVAL on July 29th.