Mimizuku No Yu is a local favourite, located half way between the Happo and the Hakuba Springs Hotel and Hakuba Station. On a clear day, the view from the outdoor bath up towards the mountains is spectacular. It's a little bit off the main foreign tourist path, and you're likely to find it busy with locals unwinding after a long day.
Open every day from 10 am to 9:30 pm in winter, closed Thursdays during the green season. A cost of 500 yen for adults.