The only daughter in the Other Minami Family. Although having a same surname with the three Minami Sister, she had no relation with them. 'Touma' contains kanji for winter. Chiaki declares her as a little brother because, "winter follows autumn". She has three brothers who didn't understand her at all. Fujioka and Riko thought Touma is a guy. She's closer to the three Minami sisters than her brothers.
Touma Minami in Minami-ke Okawari
Touma as the cover of Minami-Ke manga issue 4
When Chiaki met her at the first time, she thought that Touma is a boy. So, she decided to declares Touma as her little brother. Someday, Touma cames to Chiaki's house. Then, she met Haruka and Kana when she was atop Chiaki and they misunderstood. At first, Haruka and Kana did not realize that Touma is a girl until Touma introducted herself. Then, she decided to act as a boy. Fujioka never realize that Touma is girl although he saw Touma wearing the girl's uniform. Later, Riko thought that Touma is boy too.
Touma Minami with Chiaki Minami at Minami-Ke manga volume 3
She loves soccer and often discussing about soccer with Fujioka. In Minami-ke episode 12, she wrote a letter that she wanted new soccer ball and spike shoes for Christmas present. Her oldest brother said that she wrote the letter to Santa Claus, but Natsuki told that she wrote the letter to her brothers. She is more popular than the boys among the girls. Every Valentine's Day, she also got many chocolate from the girls. The girls thought that Touma was lot cooler than the boys.
Touma Minami's brothers
She had three brothers, The Eldest, Natsuki, and Akira that good for nothing. The eldest brother's name was never revealed. They never understand Touma and often make her upset.
Trivia
On Minami-Ke Okaeri, she got more portion than the previous two series. As Sakuraba Koharu said, she had same portion as the main characters. On every episode, she also appeared not as the supporting characters.
In voice actor credit list, her seiyuu name was below the main characters seiyuu names, on the same position.