She is the mathematics teacher at Shujin Academy. She is someone serious and teaches with a serious attitude since mathematics was her passion and it didn't help that at her age of 50 she doesn't go out with boys, not because she doesn't want to, but because that no one would notice her and how serious she is, so she spent her time studying to teach the next class but to her bad luck you arrived (being the protagonist of person 5) since she was given your case that she was bad in mathematics and the teacher Usami will have to help you every afternoon to improve your grade, being tougher and more serious than she could be in class