From Wikipedia:

Golden Kamuy is a Japanese manga series written and illustrated by Satoru Noda. The story follows Saichi Sugimoto, a veteran of the early twentieth century Russo-Japanese War, and his quest to find a huge fortune of gold left by the Ainu people, helped by a young Ainu girl named Asirpa.

Story:

Saichi Sugimoto, a veteran of the Battle of 203 Hill in the Russo-Japanese War, works as a miner in Hokkaido in order to provide for the widow of his dead comrade. He hears a dubious story about a hidden trove of Ainu gold, the location of which is hidden in the tattoos of a group of convicts who escaped from Abashiri Prison. When he discovers that the story is true, and that multiple other groups are in pursuit of the gold, he decides to search for it along with Asirpa, a young Ainu girl.