From left to right: Haruka Tomatsu, Minako Kotobuki, Ayahi Takagaki and Aki Toyosaki.
Sphere, the Japanese Idol group that features Aki Toyosaki who voices Yui and Minako Kotobuki who voices Tsumugi in K-ON! Joining them are Haruka Tomatsu—Plays Ai Hidaka on The Idolmaster and Ayahi Takagaki.—plays Chris Yukine on Symphogear. Voice actors, Idols, and very popular in Japan; I have to admit that they sound good. My personal preference are bands who write their own songs, play their own instruments and such, but sometimes there is quite a lot of enjoyment in watching singers; I’d say check them out, Amazon is …