Mari "Mari-chan" Tsutsui
About
Zodiac sign: Virgo
Class: 1-5
Anna's best friend and very protective of her. She claims to be in love with Anna. Looks moe but actually has an aggressive attitude and hates males.
She has a 25-year-old brother Masaomi who already moved out and is also married.
In chapter 20, Mattsun tells first her brother and then her his true feelings and she then believes him.