Professor Rouch

The head music teacher at Lacombrade Academy. Passionate about music, he has been in the position since Aslan's time there. He encouraged Aslan to pursue music and to enter the Paris Conservatory, but Aslan stopped playing the piano after his tuberculosis diagnosis. Later, Louis-René introduces Serge to him and he starts giving him lessons.

(Source: Kaze to Ki no Uta Wiki)