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...

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.

Shiraishi meets Ushiyama and Ienaga, who survived the explosion, but does not disclose this to Sugimoto. Sugimoto’s group encounter Inkarmat, a traveling Ainu fortune teller who Asirpa does not trust. Shiraishi takes Inkarmat to a horse race, where they win two races on Inkarmat’s predictions. Kiroranke meets old friends at the track, who ask him to ride a horse and throw the race at the behest of a yakuza boss. Shiraishi bets all his money on the last race, but it is won by Kiroranke, who defies the yakuza boss. In Barato, Ogata meets with Hijikata and joins his group.

The disguised Suzukawa attempts to bribe the 7th for Shiraishi's freedom, but he is killed Second Lt. Koito Otonoshi, who foils the plot on Tsurumi's behalf. Sugimoto flees with Asirpa, Ogata, and Shiraishi on an experimental hydrogen airship, though they are pursued by Koito. The group manages to throw Koito off the ship and escape the 7th by travelling through the Daisetsuzan mountains.

The blue-eyed man confirms he is Wilk after seeing Asirpa's makiri[b], but says he will only reveal the location of the gold to Asirpa. Wilk tells Sugimoto that he wished to raise Asirpa to be the guerrilla leader of the Ainu, and that he did not kill the Ainu to acquire the gold. Sugimoto and Wilk are suddenly shot in the head by Ogata, killing Wilk. Tanigaki pulls them out of the line of fire, but finds Inkarmat stabbed, who warns him that Kiroranke has betrayed them. Shiraishi flees with Asirpa, where they are joined by Kiroranke and Ogata, who tells them that Wilk and Sugimoto are both dead. Sugimoto awakens heavily bandaged, while Inkarmat recovers nearby, watched by Tsurumi. Assuming that Kiroranke is taking Asirpa to his associates in Karafuto, Tsurumi sends Tsukishima and Koito with Sugimoto and Tanigaki to intercept them. Asirpa has a dream in which Sugimoto tells her that he is still alive.

Asirpa reaches Kiroranke to witness his final moments and tell him that she has remembered something important. The group leaves Ako, but before going back to Hokkaido they need to find a doctor take care of Tsukishima's and Ogata's wounds.