They are sons of Riki and Fuji, and the brothers of Gin.
Ginga Nagareboshi Gin
They was born with Gin to Riki and Fuji. 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 one of them over. After Gin easily jumps on the roof, his siblings try to do the same but fail.
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.
Ginga Densetsu Anju to Jiroumaru
Neither of the siblings makes an appearance but it's mentioned that one of them is the parent of Yuki. It's unknown which one.
Ginga: The Last Wars
Neither of the siblings makes an appearance but Zion mentioned that he is grandson of one of Gin's siblings and his mother, Kinumaru is daughter of one of Gin's siblings and could be Yuki's sister or cousin, it's unknown which but it is most likely the white one.
Trivia
- The brown one is known as Hiya-n/Hiyan and the white one is known as Giyan by some fans. These aren't the real names, just whimpering sounds the pups made when Gohē hits them with his cane. These names are not official in anyway.
- The brown one's forehead dots are a slightly different color from his underfur in the anime.
- The white one is the one most likely to be the father of Yuki and Kinumaru, since he is the same color as they are.
- Neither have a major role in the series, and they only appear in the first few chapters/episodes.
Photo Gallery
See more picture in Gin's Brothers/Gallery.