Saotome Suzume♀

Suzume has been Torako's close friend since the middle school. She is usually very quiet but possesses monstrous strength and huge appetite. Despite her superior athletic ability, able to best her homeroom teacher in a one on one dodgeball match, she is in distress for looking childish and not feminine enough. In fact, she does not wear a bra and does admire Tatsuki for wearing underwears for grown ups. She also cannot swim. She seems to have no sense of shame and her behavior is very unpredictable, which often throws her friends off balance. Her name contains a kanji of sparrow (雀) and the first kanji letter of her name (早) is pronounced as 'Sa' (South), thus revealing her name's relationship with Vermillion Bird of the South (朱雀).

[From Wikipedia]