Toshie Hijikata

Toshie Hijikata is the daughter of Toshizo Hijikata and the Mobile Shinsengumi's crackshot sharpshooter. While she may be an expert on guns, she is not an excellent cook (due to having a bad sense of taste). Not much of her background is known, but apparently she cannot remember her mother's face and the only photo she has of her is missing a face. As a result, Gennai created a "mother" robot that is an exact double of Toshie, which caused some confusion.
Hijikata seems to be the most intelligent of the three girls, since she is seen relaxing in a hot spring by reading a Jules Verne book. She is also the most logical of them, to the point where Kondo often claims she's like a machine. She also strongly resembles a female version of Sesshomaru from Inuyasha, since she has similar long white hair, Chinese-influenced clothes, an icy attitude and is dismissive of slapstick.

(Source: Wikipedia)