Saotome Kyouka

Subject: Math

The teacher in charge of math.
A bewitching beauty with long, slender eyes, and is very friendly on the outside, treating her students with a kind smile, her true nature is that of a vicious sadist who enjoys treating others like toys.
Since she was young, she pretended to be the ideal student, but behind the scenes, she was a massive bully
Her sole motivation for being a teacher was to put herself in an environment where she could bully students freely.

She relishes in treating weak people like toys, but she lack any desires to rise above all others, she just wants to enjoy herself at all times.
But on the other hand, she hates being looked down upon and being interrupted in doing what she wants to do. She reveals her true self to anyone who opposes her.
She and the protagonist are similar in that regard, in that they both wish to keep others under their controls, and they get along like cats and dogs.