Ginga Nagareboshi GinEdit

The brown one is known as Hiyan (ヒャーン), and the grey\white one is known as Giyan (ギャン). 

Neither have a major role in the series, and they only appear in the first few chapters/episodes. They were denied as good bearhounds and were left to live with their mother Fuji. When Gin finishes his training with Gohei, he returns home for a brief time. The differences are already obvious when he flips Giyan over.

Later on, they were seen again when Gin finds his owner, Daisuke and mother, Fuji. They just watched as Gin tells Fuji to take care of Daisuke. They are not seen again and are assumed to be either given away to new owners or deceased.

Later, it is known that one of them has a daughter called Yuki, who has four pups, Jiromaru, Taromaru, Koyuki and Saburomaru. Either could be the father, but it is most likely to be Giyan, as he is a white colour like the daughter Yuki.

See more picture in Gin's siblings (Photo Gallery).