He is the reinforcement send by the Grania Republic military to assist Shakirov. In order for him to stay at Yukari's home he literally has to be a dog since Yukari doesn't allow anymore strangers in her house.

He hold the rank of corporal and he is a bit of a masochist.

Yukari, gave him the name "Pochi" which is common a dog's name.

(Source: Anime+)