Saichi Sugimoto hears a story about buried treasure, and joins forces with Asirpa, an Ainu girl who rescued him from Hokkaido's harsh northern wilderness, to find it.

Saichi and Asirpa head to Otaru, the largest town in the area, in search of the tattooed prisoners; they quickly learn they're not the only ones after the treasure: the army is looking for it too.

Asirpa takes Sugimoto through the Hokkaido forests, where they encounter a bear in its den; Sugimoto is impressed by Asirpa's knowledge of the land; another, older force is after the gold.

Sugimoto visits an Ainu village where he learns about their ways and culture; the next day he leaves in secret, where he is captured by the 7th and tortured.

With the help of Shiraishi, Asirpa goes to rescue Sugimoto from the 7th, but the situation is dire, and Sugimoto has already been badly injured.

Two hunters are after Retar, the last of the Ezo wolves, and the last living wolf in Japan; both of these hunters have tattoos, and Sugimoto wants them for himself.