Hisaru

is a monkey, that was lost in the jungle. It now serves as the primary personal summon of Shiroyasha Uchiha.

Background
Being a lone individual, he had literally nothing, but he didn't want to give up on life. He still needed to survive, he still wanted to repay the ones that kicked him out of the Saru Jungle. To show them, that just because he wasn't capable of preforming the task they could, that it shouldn't have resulted in a boot. He hated everything, and nearly everyone, he wanted to show his existence matter. Then he met Contract::Shiroyasha Uchiha, and finally he thought he would be able to get a kick start at his revenge. Upon meeting the young boy, instantly Hisaru didn't like him. To the point, that he attacked him. This attack resulted in a fight, that ended in a Hisaru lost. Hisaru after taking his lost learned a few things, and pledged his loyalt to Shiroyashi. Now resulting in their brother-hood like relationship.