Tōma is a tomboy girl in class 5-1 who, despite having the same surname, is not related to the Minami sisters. However, Chiaki adopted her as a little "brother" because of the same surname. She has three older brothers that know nothing about her. Her tomboy action can be said to be an influence by her brothers. The way she acts, looks and dresses causes Fujioka to actually believe that she is a boy. "Tōma" contains the kanji for "winter"; Chiaki declares that Tōma is the younger because "winter follows autumn". She is very good at sewing; she is able to make a teddy bear similar to the one owned by Chiaki.