Sugimoto Saichi, called "Immortal Saichi" for his incredible powers of survival, is panning for gold in the far north when he hears a story about buried treasure, hidden by a death row inmate. He decides to go after the treasure, but it will be a journey far longer and far more dangerous than he'd ever imagined...

Saichi and Asirpa head to Otaru, the largest town in the area, in seach of the tattooed prisoners. They quickly find out that they're not the only ones after the treasure. The army is looking for it too! Saichi has to face off against a deadly sniper, and a horrible cold front is setting in too...

Sugimoto and Asirpa are pursued by soldiers from the 7th Division. Private Genjirō Tanigaki finds Asirpa, but is fought off by Retar. Sugimoto evades capture after diving into a bear cave, whose occupant charges and kills the soldiers before succumbing to its wounds. Sugimoto and Asirpa take a baby bear found in the cave to Asirpa's village, and visit Asirpa's grandmother ("Huci"). Lieutenant Tokushirou Tsurumi, the leader of the 7th, mounts a search effort for the missing soldiers. Meanwhile, at a brothel in Otaru, Hijikata ambushes the tattooed prisoner Ushiyama Tatsuma, and offers to work with to him collect the tattooed skins.

Sugimoto leaves the village and returns to Otaru alone, where he learns of the incident with Ushiyama. He is captured by Tsurumi, who accuses him of killing the soldiers. Asirpa and Retar track Sugimoto and find Shiraishi, who tells her Sugimoto's location.

Sugimoto is tortured by twin brothers Youhei and Kouhei Nikaidō. Shiraishi breaks into Sugimoto's cell and releases his bonds, allowing him to kill Youhei. He fakes a fatal injury using Youhei's intestines, and is able to escape and reunite with Asirpa. While hunting, Asirpa and Sugimoto come across the tracks of two men: Tanigaki and Tetsuzō Nihei, a famous bear hunter.

Nihei tells Tanigaki that he wishes to hunt Retar, the last Hokkaido wolf. Asirpa and Sugimoto are joined by Shiraishi, who tells Asirpa and Sugimoto that Nihei is a tattooed prisoner. Asirpa, Sugimoto and Shiraishi track the hunters and ambush them.