I'm stuck with Seijima, can't seem to find the 4th hut, I got my repair kit ready but can't see it anywhere, Ive already beaten the bear and maxed out my hunting stats, I can drop any big animal like nothing and keep traversing the mountains just to earn megabucks from bear pelts. But I can't see a 4th hut anywhere on the map.

Will it appear later? do I need to do more story and go to the city and come back to the mountains later?

I'm (surprisingly) playing it on and off.

Ugh, Saejima's chapter. Waaay too long imo.....I'd say maybe you should do a bit more of the story in order to make it appear. I haven't done any of the side stuff yet (I save that for the 2nd playthrough) but usually that's how it works in Yakuza. Some side stuff opens up the more you progress. If nothing else, search every little corner possible and try talking to whoever you can.

That's the one thing annoying thing about the Yakuza games. Guidance for some of the side stuff can be really tough.