Girl7

Girl7 is an anime-only band consisting of seven members, that made its first appearance in the episode Clean-up! on a flyer inside of a music store. Azusa and Mio had wished for more members for their own band after seeing Girl7's advertisement.

Musical Profile
Girl7 is a pure girl group, but the musical orientation is unknown.

The fact that they have their own advertisements might mean that they are fairly skilled and famous.

Line-Up
The band consists of seven female members, hence the wordplay of the band's name. The full line-up is unknown, but one member is clearly the drummer while another one is a vocalist. Four of the other members play guitar or bass. The position of the last member is unknown.