Vegetarian's Japan Guide

Shiriyaki Onsen – Where You Bathe in a Natural River

If you love adventures and visiting hidden gems, Shiriyaki Onsen (尻焼温泉) in Gunma Prefecture is a perfect spot for you. Instead of a hot spring pool, you can bathe in a natural river with hot springs flowing. You won’t be asked to bathe naked. It is optional. However, as photography is allowed there, just remember to bring towels and a swimming suit to cover yourself!

Shiriyaki Onsen’s History

If you can read Japanese, you might find the hot spring’s name funny because “Shiriyaki” means burning bottom! Apparently, the name came from the fact that people would go there to treat hemorrhoids. They would dig a hole in the riverbed and soak only their buttocks in hot water to treat it. Nowadays, the river itself has a more elegant name, “Kawa no Yu (川の湯)”.

Shiriyaki Onsen’s hot spring comes out from the bottom of the riverbed of the Nagazasasawa River (長笹沢川). And because the dam upstream releases water into the river as well, until a decade ago, it was hard to find a spot in the river with adequate temperature to bathe in.

But things have changed! The part of the river where hot springs are gushing out is dammed to create a simple bathing area in the river.


How to Enjoy Shiriyaki Onsen

Before departing for Shiriyaki Onsen, it is best to change into your swimming suit as there are no changing rooms at Shiriyaki Onsen. You can always wear something warm over the swimming suit if the weather is cold.

As Shiriyaki Onsen is located on the riverbed of the Nagazasasawa River, the first thing to enjoy there is the rare natural scenery, which is especially amazing in the fall foliage season. From the bridge on the way to the hot spring from the free parking lot, you will see steam floating above a section of the river, indicating where you will be bathing. Although it might be tempting to head straight to Shiriyaki Onsen, we recommend staying on the road you walk on to overlook the hot spring from above first.

It might surprise you but Shiriyaki Onsen can be crowded, especially during weekends and public holidays. So since it is accessible 24/7 and free of charge, be there in the early morning to nab the good spots in the bathing area! If you stay at one of the ryokans close to it, you can adore the scenery dyed with the sunrise’s orange sunshine!

And what is the popular spot in the bathing area? It is where the hot springs are emerging up from the riverbed. To spot them, you just need to see where the bubbles appear (^_-)-☆.

Note that while there are ryokans close to Shiriyaki Onsen, there are no restaurants or convenience stores, so packing some snacks or a lunch box would be a smart idea.

Ⓒ ググっとぐんま観光宣伝推進協議会

☛ Check the weather forecast before heading to Shiriyaki Onsen. The hot spring’s temperature will be lower on a rainy day so you might not be allowed to bathe.
☛ Algae would grow on the riverbed, making it slippery. Please walk carefully when you bathe in Shiriyaki Onsen.
☛ The deepest point of the bathing area is around 150 meters, so be careful to avoid accidents.
☛ Swimming suits and bath towels are prohibited from bathing in the indoor pool of the small hut next to the river.
☛ For your safety, don’t visit Shiriyaki Onsen after sunset, especially if you are a female.

☛ There is a toilet close by.
☛ In winter, the water temperature is more stable, probably due to less discharge from the dam.
☛ If you like craftwork, visit Nedofumi no Sato (ねどふみの里) nearby to learn how to make Konkon Zōri straw sandals. The straws used to make the sandals are first soaked in Shiriyaki Onsen’s water before being made into sandals or straw mats.

The Accommodations Close to Shiriyaki Onsen

  • Hoshigaoka Sansō (星ヶ岡山荘)
    • Two of the guestrooms have a hot spring pool attached.
  • Hotel Kohzansou (ホテル光山荘)
    • If you have special dietary requirements, they won’t be able to accommodate it if you book to stay on Saturday.
  • Shiriyaki Onsen Shirane no Mieru Oka (尻焼温泉 白根の見える丘)
    • A private hot spring pool overlooking Mt. Shirane is available for you to book.
    • Japan’s Top 100 Spring Water is used to make homemade tofu served at the ryokan.

Important: for the above three ryokans, the below applies:
☛ Meals can be served without meat and fish if you inform them beforehand. However, the broth and sauce will most likely contain fish extract.
☛ They currently accept bookings via phone call, their official Japanese website, or Japanese hotel booking platforms.

How to Get to Shiriyaki Onsen

  • From JR Naganohara-Kusatsuguchi Station (長野原草津口駅), take bus services bound for Hanashiki Onsen (花敷温泉) and get off at Hanashiki Onsen. It will then be a 10 to 15-minute walk from the bus stop.
    • Refer to Kusatsu Onsen’s Access Information to know how to get to JR Naganohara-Kusatsuguchi Station.
    • Refer to HERE for the bus service’s timetable. You can translate it using Google Chrome’s translation function at the right of the address bar.
    • The bus trip will be around 40 minutes.
  • Shiriyaki Onsen is around a 30-minute drive from Kusatsu Onsen. It will be another 10-minute walk from the parking lot.

Soba Restaurant Kuni Nonoya (そば処 六合 野のや)

A nice soba restaurant close to Shiriyaki Onsen is Nonoya. The restaurant is renowned for its maitake mushroom dishes.

While maitake mushroom is Kuni Village‘s specialty, with many restaurants in the area selling maitake mushroom dishes, you can hardly find one that a maitake farm operates! Because the mushrooms are sent straight to the restaurant after harvesting, the freshness and deliciousness are guaranteed. And you will surely be surprised by the size of the mushrooms!

Thus most of the dishes offered at Nonoya have maitake mushroom as the main ingredient. In fact, many regulars would add a bowl of rice topped with cooked maitake mushroom or tempura maitake on top of their bowl of maitake soba noodles. The thick and juicy maitake mushroom is just so delicious that you will want seconds!

The soba noodles made from buckwheat from Kuni Village and water sourced from Nozori Lake are another reason that Nonoya’s noodle dishes are popular amongst locals and tourists. Other ingredients, such as rice and vegetables, are also from Kuni Village.

☛ Nonoya usually starts serving noodles made from freshly harvested buckwheat in mid-October.
☛ Arrive early to avoid queueing up.

Important: The noodle dipping sauce and broth are not vegetarian.

Soba Restaurant Kuni Nonoya’s Business Hours and Access Information

  • Soba Restaurant Kuni Nonoya is open daily from April to December from 11 am to 3 pm or until sold out.
    • The restaurant closes on Wednesdays and Thursdays from April to December.
    • From January and March, the opening days aren’t set. It is best to call the restaurant at +81-279-95-5478 to confirm before visiting.
  • From JR Naganohara Kusatsuguchi Station (長野原草津口), take Kuni Chiku Rosen Bus (六合地区路線バス) and get off at Hikinuma (引沼).
    • Note that bus services are limited. The Japanese timetable can be found on Nakanojō’s website HERE and click “六合地区路線バス”.

Kiku Tofu Shop (㐂久とうふ店)

The Kiku Tofu Shop located diagonally opposite from Soba Restaurant Kuni Nonoya is another recommended food-related spot close to Shiriyaki Onsen. Whether it is ordinary tofu or other soybean products such as deep-fried tofu and soy milk, the products made there have a rich taste!

Ⓒ 一般社団法人 四万温泉協会

But as much as we want to purchase more of Kiku Tofu Shop’s products, it is hard to carry tofu or soy milk around while traveling. So remember to utilize the eat-in space to enjoy various tofu products with complimentary soy sauce and cutlery!

Kiku Tofu Shop also sells delicious tofu and Pinto bean ice cream!

The Inari Sushi made from freshly fried bean curd is another must-eat item at Kiku Tofu Shop!

Kiku Tofu Shop’s Opening Hours and Access Information

  • Kiku Tofu Shop is open daily except Wednesdays from 8:30 am to 6 pm.
  • From JR Naganohara Kusatsuguchi Station (長野原草津口), take Kuni Chiku Rosen Bus (六合地区路線バス) and get off at Hikinuma (引沼).
    • Note that bus services are limited. The Japanese timetable can be found on Nakanojō’s website HERE and click “六合地区路線バス”.

Discover Attractions in Kusatsu Onsen

Click the photo for more information about Kusatsu Onsen’s attractions!

For an authentic hot spring experience, we recommend visiting Kusatsu Onsen, a 30-minute drive away.

In addition to the public and communal bathhouses, Kusatsu Onsen has much to offer. Whether it is soba noodles, traditional sweets or outdoor activities, such as obstacle courses and skiing, you surely won’t be bored at Kusatsu Onsen!

For more information, refer to our article on Kusatsu Onsen (=゚ω゚)ノ.