Miyabi

Shinobu's little sister who has chosen the field of "magical summoning" rather than ninjutsu. She dislikes Onsokumaru (a mutual feeling) and believes that her elder sister should switch fields and become a magical summoner like herself. Though just ten years old, she is something of a prodigy and is skilled enough to consistently defeat Onsokumaru when he gets on her nerves. In one episode, Onsokumaru was stuck on her dress and took her flying. This softened Miyabi's feelings towards him.

(Source: Wikipedia)