She's the Sacrifice Unit of Sleepless. Kinka and Ginka together are Sleepless—ones who do not sleep. They quickly entered volume 2, were defeated by Soubi and therefore had to surrender the envelope containing important information to Ritsuka.

They were an alright pair but obviously they did not have the skills to defeat Soubi, maybe some time in the distant future they may become a tenth as powerful as Soubi is alone.

(Source: Novellalive)