BCS

BCS is a band consisting of at least four members.

Musical Profile
The band seems to be fairly skilled and famous, able to perform in a gigantic musical festival as the "Natsu Rock Festival" (which is most likely an allusion to the Fuji Rock Festival, the largest outdoor music event in whole Japan), where they could enthuse a crowd of many thousands of people with their music.

Style
The band's music is Punk Rock, which can be heard in their song "Rule".

Trivia

 * The band was neither named in the manga, nor the anime itself. Instead, the name derives from the anime credits and the third of the "Official Band Yarouyo" albums, which contains their song "Rule".