Reiji Karasuma

A third-year high school student. He's the drummer of the band εpsilonΦ.

The adopted child of the Karasuma Family, who has served the Ujigawa Conglomerate for a long time. A cool and level headed individual with a slight cleaning complex and a keen mind. While he looks polite from his appearance, he looks down on all of humanity. He obeys Shu's every whim and looks after his daily needs, assisting in his "playtime" in its entirety and loathes Shu due to it. Contrary to his usual behavior he plays the drums rather powerfully.

(Source: ARGONAVIS from BanG Dream! Wiki)