Yoshie Shimizu

Yoshie Shimizu (清水 ヨシエ, Shimizu Yoshie) is a student at Kaimei High School who was going to play drums in Yabasawa's band for the Kaimei Rock Festival, until all of the band members fell sick. She was also mentioned when Switch was gathering info on the Ghost Incinerator incident.

Manga Debut: Chapter 50 (Sketchbook)
Anime Debut: Episode 16 (Kaimei Rock Festival)

(Source: SKET Dance Wikia)