Doa Yoshino

Ittō-ryū swordswoman who is quite small. Her primary weapon is an odd knife which is fashioned from a spearhead. She appears in the later chapters as one of Ittō-ryū's new recruits. Doa always travels with her friend Isaku and the two have developed complementary fighting styles. This usually consists of Doa providing the offense with her speed and dagger, while Isaku provides the defense with his armored arms. Her tendency to jump right into battle with little to no provocation often lands her and Isaku in trouble. She ends up befriending Asano Rin. She and Isaku are both originally from Hokkaido, where Doa lived defending Ainu land from Samurai who attempted to take it by force, despite the fact she is not Ainu herself. She previously went by the names "Kuichiru" and "Towa".

(Source: Wikipedia)