The 7th Division's Private Hyakunosuke Ogata and former Shinsengumi Vice Commander Toshizou Hijikata find themselves on opposite sides of a gang war in Barato after hearing rumors of the Hidoro gang possessing an escaped prisoner's tattooed skin. With a lead to the hidden Ainu gold close at hand, the two gladly take up arms but a betrayal will force both sides to think twice before carelessly jumping the gun.

The race to obtain the lost Ainu gold is nearing its peak, as even more formidable ex-prisoners are set on keeping their tattooed skins intact. Saichi The Immortal Sugimoto and Asirpa can finally move forward together, but Asirpa's time with Kiroranke and Ogata Hyakunosuke has slightly altered her ambition and strengthened her determination. As their party leaves the Russian territory, they gain a peculiar follower. Meanwhile, Toshizou Hijikata's crew makes major moves to get invaluable skins, falling into the poisonous trap of a dangerous convict. Although each group possesses a strong advantage over the others, even First Lieutenant Tokushirou Tsurumi—the most powerful and ruthless contender—cannot advance without Asirpa's help. However, his ominous plans for when they will inevitably meet remain a mystery.

In early 1900s Hokkaido after the Russo-Japanese war, Saichi Sugimoto tirelessly pans for gold. Nicknamed Sugimoto the Immortal for his death-defying acts in battle, the ex-soldier seeks fortune in order to fulfill a promise made to his best friend before he was killed in action: to support his family, especially his widow who needs treatment overseas for her deteriorating eyesight. One day, a drunken companion tells Sugimoto the tale of a man who murdered a group of Ainu and stole a fortune in gold. Before his arrest by the police, he hid the gold somewhere in Hokkaido. The only clue to its location is the coded map he tattooed on the bodies of his cellmates in exchange for a share of the treasure, should they manage to escape and find it. Sugimoto does not think much of the tale until he discovers the drunken man's corpse bearing the same tattoos described in the story. But before he can collect his thoughts, a grizzly bear—the cause of the man's demise—approaches Sugimoto, intent on finishing her meal. He is saved by a young Ainu girl named Asirpa, whose father happened to be one of the murdered Ainu. With Asirpa's hunting skills and Sugimoto's survival instincts, the pair agree to join forces and find the hidden treasure—one to get back what was rightfully her people's, and the other to fulfill his friend's dying wish.

In Hokkaido, it is rumored that there is a stash of hidden gold. This gold was supposedly stolen by a man who killed the original Ainu owners; and before being captured and imprisoned by the police, he hid it in a secret location. In order to relay the gold's location to his comrades on the outside, he tattooed the map on the bodies of his cellmates and promised them a share of the gold—provided they managed to escape and find it. In Golden Kamuy 2nd Season, First Lieutenant Tokushirou Tsurumi plans to give the 7th Division an advantage in the war for the tattoos by getting a taxidermist to create skins that only he can distinguish as fake. Meanwhile, Saichi The Immortal Sugimoto, Asirpa, and their companions continue their hunt for the skins by following a strange rumor: a thief who broke into a home in Yubari found taxidermied human corpses, among which was a torso with strange tattoos.