Due to its unique geographical location, aside from the larger hot spring pools, there are also many very small hot spring pools in the mountains.
The larger ones naturally fell into the hands of various resorts, since they had the financial and influential power; the smaller ones were more secluded, and most people were not willing to come, so they were mostly occupied by locals, who turned them into tiny farmhouse hot spring inns.
If it were just hot springs alone, business would naturally be limited, and with the location being remote, even with lower prices, there wouldn't be much business. Because of this, the locals found another way, adding many colorfully dubious side industries to these hot spring inns...
From the first inn, the business gradually developed and spread, creating an ever-growing industry chain, eventually forming a region that was not large, but where the entertainment industry was exceptionally developed.