Tsukishiro Kagura

The protagonistr's classmate and Miko's best friend.
She is wearing a men's uniform shirt for some reason.
She's like a class mascot, called "Princess Kaguya" because of her name, her hairstyle, and the sleeves of her fluffy shirt.

She is a young lady who speaks in honorifics to everyone.
She is a member of the Kendo club, but she is closed due to various reasons.
Miko is also a roommate in the girls' dormitory.

"Eh? Is it in my sleeve? ... It's a secret."