SI-VIS: The Sound of Heroes Episode 21 English Subbed

SI-VIS is a co-ed music group, led by Yosuke, shaking up the global music scene with their unmatched vocals and performances. However, they are actually heroes in disguise, battling against mysterious forces threatening the world. They convert audience energy at live performances into combat power. Luckily, the battles appear to be ordinary concerts to the public, keeping their identity a secret. (Source: Crunchyroll)