Golden Kamuy: Inazuma Goutou to Mamushi no Ogin/Shimaenaga

After walking out of the Russo-Japanese War with a reputation that earned him the nickname 'Immortal Sugimoto,' Saichi Sugimoto is now chasing something arguably harder to survive — a hunt for hidden Ainu gold, with a map literally carved into the skin of escaped convicts. This OVA from Brain's Base adapts the Inazuma Goutou and Mamushi no Ogin chapters along with the Shimaenaga side story, pulling from the Golden Kamuy manga's seinen roots to deliver a tight, self-contained episode set in early 1900s Hokkaido. Sugimoto and his partner Asirpa, a sharp young Ainu hunter who knows the land better than anyone, cross paths with a pair of particularly dangerous bandits — the kind of people who got their names by earning them the hard way. The appeal here is the same thing that makes Golden Kamuy work as a whole: it treats Ainu culture with genuine respect while also being a wild, violent treasure hunt full of characters who are all a little unhinged. The historical setting feels lived-in rather than decorative, and the action carries real weight. If you've been into historical seinen like Souten Kouro or darker adventure fare like the Berserk films, this sits comfortably in that space — grounded, brutal, and surprisingly educational. If you already follow the Golden Kamuy series, this fills in story you want. If you don't, it's a good taste of what makes the whole thing worth your time.