Ginga Densetsu: Anju to Jiroumaru

The story begins in Futago Pass, a paradise for dogs where peace reigned thanks to the Ouu Army's exploits. Orion, the pup of Ouu Army Commander Weed, spent peaceful days with his newborn siblings: his older brother Sirius, younger brother Rigel, and younger sister Bella. But fate would not grant Orion tranquility. Suddenly, a natural disaster struck the mountains of Ouu, shattering the paradise. Orion and his siblings were scattered far and wide! (Source: Nihon Bungeisha, translated)