Inagaki Onsen, despite being on the smaller side, definitely has its charm. As part of a hotel resort it's a bit hidden, but the receptionist will be sure to guide you. At the affordable rate of 400 yen, this onsen is a great place to relax on a cold night. The water is a bit salty though, so be sure to keep your mouth closed while bathing.
In addition to the bathing area and hot water pool, there is a sauna and a small cold water bath. The best part about this onsen, however, is definitely the rotenburo. Not all rotenburos are created equally, and this one has a great, traditional Japanese environment: hanging lanterns, a rock waterfall, and beautiful, surrounding greenery. FYI: This area is sex-separated and well covered, so rest assured, no one will be peeking.
The Skinny: Somewhat small, but compensated by a great rotenburo
Price: 400 yen
Hours: 10:00 - 19:00 (except Mon and Thurs, 13:00 - 19:00)