Rui Yashio  

, 八潮 瑠唯

Rui is an accomplished musician who has been playing the violin since childhood. Despite her success, she was defeated by Rinko Shirokane in a competition and felt that she lacked true talent. Consequently, she stopped playing the violin. Additionally, Rui serves as a member of Tsukinomori Girls Academy's student council, initially attending Morfonicas band practices to monitor their activities.