Often called Otae, she is the older sister of Shimura Shinpachi. The Shinsengumi have almost accepted her as the de facto lady boss, or rather the consort of their boss Kondou Isao, by calling her nee-san.
When Otae was younger, she beat up the bullies who made fun of Yagyuu Kyuubei. From that moment on, Otae and Kyuubei were close childhood friends. Kyuubei greatly admired Tae because she was strong and carried even the heaviest burdens with a smile on her face. When Kyuubei saved Tae from her debt-collector’s abuse and lost her eye in the process, Tae promised Kyuubei to marry her and become her new left eye.