Sanko Onsen: A Hidden Hot Spring Retreat by Lake Kussharo in Eastern Hokkaido

During my recent trip to Eastern Hokkaido, I wanted to experience a local hot spring, and that’s how I found Sanko Onsen, a small inn located on the shores of Lake Kussharo.

This cozy inn, run by a friendly couple, has only four rooms and is well known for its open-air hot spring baths and warm hospitality.

The price was also very reasonable at just ¥7,500 per night, including two meals. (*Price as of my stay in 2014.)

After staying here, I got to enjoy soaking in the spacious outdoor hot spring under the starry sky, experience warm yet unobtrusive hospitality, and chat with the owner and regular guests.

It was a completely different kind of luxury from a high-end hotel—truly a hidden gem!

Sanko Onsen: A Hidden Hot Spring on the Shores of Lake Kussharo, Eastern Hokkaido

Here’s the entrance to Sanko Onsen. I learned that Lake Kussharo is home to the mythical creature “Kussy,” similar to Scotland’s Loch Ness Monster. (This was my first time hearing about it!)

At the entrance, I was greeted by Kinta, the inn’s friendly dog. He was incredibly affectionate and even tried to climb on me while I was taking pictures!

A great welcome service, but doesn’t he have any sense of caution?

The exterior had the perfect “hidden hot spring” vibe. This was my first time staying somewhere like this.

I cautiously stepped inside.

The owner quickly spotted me and welcomed me in.

I signed in at the lobby.

Interestingly, Sanko Onsen received the Rakuten Travel Award in 2011 and 2013. It has an impressive 4.8-star rating—an exceptionally high score for any hotel or inn. I soon understood why.

The room was a simple yet spacious 8-tatami mat Japanese-style room, perfect for two people.

Soaking in the Open-Air Hot Spring Under a Starry Sky—A True Luxury

Since it’s called “Sanko Onsen,” of course, I had to take a dip in the hot spring!

I quickly changed into my yukata and headed to the separate bathhouse.

It was February, so there was plenty of snow and freezing temperatures, but the thought of warming up in the hot spring made it all worth it.

Hot spring time!

Inside the changing room, a wood-burning stove kept the place warm.

Here’s the open-air bath—spacious and inviting!

The bath is divided into four sections by wooden partitions, with the hottest water closest to the spring source and cooler water further away.

Since it was below freezing outside, I needed to rinse off quickly and jump in to warm up.

(*Be careful in winter, as the floors can be icy!)

In winter, the first or second hottest bath had the perfect temperature.

Sitting alone in the spacious, sulfur-scented hot spring while gazing at the stars—it was a completely different kind of luxury compared to high-end hotels.

The inn also has an indoor bath, though I didn’t use it this time. It looked just as inviting.

Simple Yet Thoughtfully Prepared Home-Cooked Meals

Dinner was served in a private room separate from the main lodging.

Dining alone in a cozy space like this had its own charm.

Hokkaido is famous for its fresh seafood, but many inns serve similar set menus.

Sanko Onsen includes some sashimi but primarily serves home-cooked meals. This means that even if you visit multiple times or stay for several nights, the food won’t become repetitive.

Each dish was prepared with great care, and everything was delicious.

And of course, Sapporo Beer always tastes great! (Like most inns, drinks are charged separately.)

The rice was also delicious!

Enjoying Conversations with the Owner and Other Guests – Plus a Relaxing Morning Bath & Breakfast

After dinner and another soak in the hot spring, I spent the evening chatting with the owner and another guest in the shared lounge area.

We enjoyed some beer and sake while sharing stories—it was a great experience.

Of course, if you prefer, you can also relax alone in your room or spend time with your family.

The next morning, I naturally had to take another dip in the open-air bath.

Birdsong filled the air as I soaked in the warm water—what a perfect start to the day.

Let’s get in!

Ahhh… so relaxing.

I didn’t see any wildlife during my stay, but I did notice some animal tracks—perhaps from an Ezo squirrel or another local critter.

If you’re lucky, you might get to see wild animals while enjoying the bath.

This is an authentic onsen, with naturally flowing, mineral-rich spring water.

Looking back toward the main building, it has a charming rustic feel.

Since it was winter and everything was covered in ice and snow, I couldn’t see much of Lake Kussharo.

However, I heard that the lake is visible from the bath during the warmer months.

I’d love to return in spring or summer!

After my bath, it was time for breakfast.

Just like dinner, breakfast was a generous spread of homemade dishes. Everything was delicious.

As I checked out, Kinta, the friendly dog, gave me an enthusiastic send-off.

The warm hospitality of the owner and Kinta made my stay even more memorable.

Thank you for everything!

I’ll definitely be back in a different season!

Final Thoughts

I had always wanted to visit a secluded hot spring, and with its high ratings and great reviews, Sanko Onsen did not disappoint.

This was an incredible experience, and I’d love to return sometime between spring and autumn to see how the scenery changes!