No, that is most certainly the math teacher. No one else has that 'fro. I do admit to being confused, though; it says 'Ms.', but not only does Miyahara not look like a woman in the least bit, but I recall a 'he' being thrown around once. I don't know. This would be much simpler if Japanese had more gender-specific pronouns.
Either way, even the character artist agrees, Ms. Miyahara sure is funky.
