Mizuno Azusagawa

Tsukinos little sister. Since Tsukino is a love child Mizuno has the support of her father. They have a bit of a rivalry over Azuma whether for his baking skills or his heart. She is quite competitive and not very honorable. Once Azuma told her that if he won against her in the newcomers competition then she had to call Tsukino oneesan as a younger sister should. In exchange if he lost he would have to work at her store. Mizuno lost but at first refused to call Tsukino oneesan. She later consented to it but also came up with another gamble: if Azuma lost against Koalachan or Mokoyama then Tsukino would have to give up her rights to owning Pantasia complete with contract. Azuma and Mokoyama tied but Mokoyama gave up making Azuma the winner. As of what happened to the ownership of Pantasia Mizuno is still going for it. Source: Wikipedia