Kosaka Miyori

"Do not misunderstand. I merely wish to prove you are unworthy of my Lady."

An expressionless maid.
She transfers to the school to investigate the target of her mistress Matsuri's affections.
Unwilling to hand her over to anyone, she deliberately makes things difficult for the protagonist.
However, driven by her devotion to do what’s best for her lady, she gradually warms up to him as she observes his behavior.
She also appears to possess several secret tools known as the "Seven Maid Treasures."

Class: Hinamori Academy, Class 2-1
Height: 149cm
Birthday: September 9th
Likes: Her mistress, small animals (though she thinks she’s good at hiding this)
Dislikes: Anyone who dares approach her lady with ill intentions

From Steam

 Although she did put a maid act, later revealed in her route that she was not really a maid. But actually the daughter of the wealthy family that she said she's working for.

 She is  Matsuri  's Older sister.