Sakakibara Kaoruko

A teacher at the academy, and the deputy of the entire music department. There is another head, but she is the true leader of the academy.
She is a serious and domineering person. That's why she's strict about discipline and teaches student how to behave as according to traditions. Despite this, she still respects those who ask questions and concerns.
A 'Jack-of-all-trades' to her colleague due to her many abilities.
The protagonist is her enemy, and is always keeping an eye on him for any misconduct, which eventually lead to a probation period.