From Chibi Manga:

Meeting sensei, I came to know real love...

Akaha, who's known as the cool beauty throughout the school. She has a boyfriend she's going out with, but she doesn't understand real love. One day, after being saved by Kano-sensei from a dangerous situation, the two went out for dinner...

When you're in real love, you can't be calm about it.
That kind of feeling, she knew after meeting sensei.

Sad, trembling, forbidden love!