Disclosure: Tabilane earns a commission if you book through links on this page, at no extra cost to you. This does not affect our recommendations. See our Affiliate Disclosure for details.
I came to Kusatsu Onsen on a whim during my third winter in Japan, expecting a tidy little resort and one good bath. What I got instead was a town built around a river of steaming mineral water that runs right down the middle of the main square. You smell the sulfur before you see it. Then you turn a corner and there it is — the Yubatake, hissing in the cold air like the town is breathing.
Quick Answer / The Short Version
Kusatsu Onsen is a highland hot spring town in Gunma Prefecture, sitting at roughly 1,200 meters of altitude, and it is consistently rated Japan's top town for return visits. Its centerpiece is the Yubatake ("hot water field"), a steaming open channel in the town center that cools the spring water before it reaches the baths — it is free to view, lit up at night, and the single most photographed spot in town. From Tokyo you have two real options: a direct highway bus (about 4 hours, roughly ¥3,000–4,300 one way), or a faster limited-express train plus a short local bus (about 3 hours total, but closer to ¥6,000). The two routes genuinely differ in both time and price, so check current schedules and fares before you commit. You can do Kusatsu as a day trip, but the town is far enough from Tokyo, and best after dark and just after dawn, that I'd plan to stay one night.
The Yubatake, Kusatsu Onsen's steaming centerpiece, glowing under its evening lights. (Image: 掬茶 via Wikimedia Commons, CC BY-SA 4.0.)
Why Kusatsu Tops Japan's Onsen Rankings
Japan takes its hot spring rankings seriously, and Kusatsu wins most of them. Kusatsu holds #1 in Japan's most-watched onsen rankings — see how Japan ranks its onsen towns for the full picture of how these surveys actually work.
The headline numbers: Kusatsu is #1 in "Nippon no Onsen 100-sen" for 23 consecutive years; #1 in Jalan's "most want to revisit" ranking, 2025 & 2026 (source: Kankō Keizai Shimbun / Jalan / Nippon.com). Worth being precise here, because a lot of English-language pages get it wrong: Kusatsu is #1 in the repeat-visit rankings — the towns people most want to go back to. Jalan also runs a separate "want to visit once" ranking, an aspirational list, and that one is led by Yufuin, with Kusatsu in third. So when you read that Kusatsu is "Japan's number one onsen," it's the loyalty vote it keeps winning, year after year.
There's a reason people return. Kusatsu's water is strongly acidic — around pH 2.1 — and its natural discharge of roughly 32,300 liters per minute is the largest of any onsen town in Japan. The practical upshot is that nearly every bath here runs on genuine, untreated source water rather than recirculated, reheated supply. You feel the difference. The water has a real bite to it.
Getting to Kusatsu from Tokyo
This is the part most travelers get tangled in, so I'll lay it out plainly: there are two sensible ways to reach Kusatsu from Tokyo, and they are genuinely different trips. One is a single direct bus. The other is a fast train to a small mountain station, then a short connecting bus. Neither is "the obvious winner" — it depends on where you're starting and what you value.
By Direct Highway Bus
The simplest option is a direct JR Bus Kanto highway bus from Tokyo straight to the Kusatsu Onsen bus terminal, with no transfers. Direct departures run from Busta Shinjuku and Tokyo Station (Yaesu side); the one-way fare runs roughly ¥3,000–4,300 depending on the season (advance and off-peak fares are lower; peak dates run to the top of that range), and the total journey takes about 4 hours. Confirm the current timetable with the operating company before you build your day around it — highway bus schedules and fares change seasonally, and seats on the popular runs fill up. The trade-off is comfort over speed: you sit once, you arrive once, but you're at the mercy of expressway traffic.
By Train + Local Bus
The other route splits the trip in two. You take a limited-express train (the "Kusatsu-Shima" service) from Ueno toward Naganohara-Kusatsuguchi Station, which takes about 2 hours 20 minutes (a reserved seat is around ¥5,400), then transfer to a JR Bus Kanto local bus bound for Kusatsu Onsen, which takes a further 25 minutes or so (about ¥710). All in, the train-and-bus route runs roughly ¥6,000 and lands you in town in about 3 hours — faster than the bus, but noticeably pricier. This is the route to choose if you're already holding a rail pass or you want the flexibility of frequent trains. The catch is the connection: the local bus from Naganohara-Kusatsuguchi runs on its own schedule, so check that your train arrival lines up with a departing bus rather than assuming they meet.
A quick warning from experience: the bus stops up here are not generously signed in English, and the last connections of the evening leave earlier than you'd expect for a tourist town. Note your return times before you settle into a long soak.
Day Trip or Overnight?
You can technically see the Yubatake, soak in a public bath, and catch the Yumomi show all in a single daylight visit. But Kusatsu rewards staying. The Yubatake is lit up at night and the crowds thin out after the day-trippers leave; the next morning, just after dawn, you can have the square almost to yourself. Doing the round trip from Tokyo and back in one day means racing the clock both ways and missing the two best windows the town has. For a place this far into the mountains, one night is the difference between checking a box and actually feeling why people keep coming back.
The Yubatake — Kusatsu's Steaming Heart
The Yubatake is the reason the town looks and smells the way it does. Spring water surfaces at the source far too hot to bathe in, so instead of cooling it with cold water — which would dilute the minerals — Kusatsu runs it through long wooden channels in the open air, letting it shed heat naturally before it's piped to the baths. The result is a slatted field of cascading, sulfur-yellow water in the dead center of town, framed by stone railings and, in the evening, soft lighting.
The Yubatake itself is roughly 60 meters long and 20 meters wide, and about 4,000 liters of spring water flow through it every minute — water that surfaces at well over 90°C and sheds heat in the open wooden channels before it is piped to the baths. Kusatsu's total natural discharge, of which the Yubatake is only one part, is the largest of any onsen town in Japan. The scene itself needs no exaggeration. It's free to walk up to, out in the open day and night, and it changes character through the day: businesslike and steaming in the morning fog, then theatrical once the lights come up after dark. Stand at the downhill railing and you get the full length of the channels with the town climbing the slope behind it. That's the shot everyone comes for.
Free and Paid Baths — What Visitors Can Actually Use
New to onsen? Read our first-time onsen etiquette guide first — Kusatsu's water is strong and the local bathing customs are particular, so it pays to know the basics before you undress.
Here is the single most misunderstood thing about Kusatsu, and where most English guides go fuzzy: the town has a large number of small communal bathhouses, many of them genuinely free, but most of them are reserved for local residents, not visitors. Walking into the wrong one isn't a ticket-price issue — it's a community-vs-tourist line. So the practical question isn't "are the baths free?" It's "which baths can I actually use?"
Public Bathhouses Open to Visitors
A handful of Kusatsu's free communal bathhouses are open to visitors as well as residents. The ones most commonly cited as visitor-accessible are Shirahata-no-yu, Chiyo-no-yu, and Jizo-no-yu — all free communal baths open to visitors as well as residents. Their opening hours differ from one bathhouse to the next and can shift seasonally, so confirm the current times with the Kusatsu tourism association before you go. These are simple, traditional bathhouses: no frills, very hot water, and a short list of unspoken rules. Rinse thoroughly first, ease in slowly, and don't be surprised if a regular gently corrects your technique. The water in these is potent — keep your first dip short.
Sainokawara Open-Air Bath
If you want a large open-air soak with room to stretch out, Sainokawara Rotenburo is the headline experience — a spacious outdoor bath set in a riverside park at the edge of town, particularly atmospheric when the surrounding woods are dusted with snow. Admission is ¥800 for adults and ¥400 for children, and it's open 7:00–20:00 from April through November and 9:00–20:00 from December through March, with last entry at 7:30 p.m. either way. There's also a combination pass — the Choina San-yu Meguri tegata (¥2,100 for adults, ¥1,050 for children) — that bundles one entry each to Sainokawara and the town's two other paid baths, Otaki-no-yu and Goza-no-yu. It works out about ¥800 cheaper than paying the three separately, and it has no expiry date, so it's worth it if you plan to bath-hop. Hours and prices can change, so confirm at the official Kusatsu Onsen site before you go.
Sainokawara Park, the steaming riverside walk at the edge of Kusatsu that leads to the large Sainokawara Rotenburo open-air bath and a free footbath. (Image: Aspere via Wikimedia Commons, CC0.)
Free Footbaths
If you'd rather not fully commit to a bath — or you've already soaked and just want to keep warm while you wander — Kusatsu has several free footbaths (ashiyu) scattered around town. The ones near the Yubatake, in front of Jizo-no-yu, and over in Sainokawara Park are free and open through the day. Pull off your socks, sit on the edge, and watch the steam rise. It's the most relaxed way to sample the water, and it's the one bathing experience here that asks nothing of you.
The Yumomi Performance (湯もみ)
Because Kusatsu's source water is so hot, locals historically faced a problem: cool it down enough to bathe without watering down the minerals. Their solution was yumomi — stirring and slapping the water with long wooden paddles to release heat, done in rhythm and traditionally accompanied by folk songs. You can watch this performed at Netsu-no-yu, the dedicated hall right beside the Yubatake.
I caught an afternoon show and it's more charming than gimmicky — a row of performers in happi coats working the paddles in unison while the room fills with steam and song, sometimes pulling a few visitors up to try it. There are usually six performances a day — three in the morning (9:30, 10:00, 10:30) and three in the afternoon (15:30, 16:00, 16:30) — each running about 20 minutes, with viewing tickets around ¥700 for adults and ¥350 for elementary-school children. Those are the regular-season times (March through November); in winter (December through February) the three morning shows start half an hour later. Times can also shift on holidays and special-event days, so check the day's schedule when you arrive rather than relying on an old listing. It runs only a few times a day, so it's worth planning your visit around one of the sessions.
The yumomi performance at Netsu-no-yu, where wooden paddles cool Kusatsu Onsen's scalding source water. (Image: Σ64 via Wikimedia Commons, CC BY 4.0.)
Best Time to Visit
Kusatsu is good year-round, and the two strongest seasons pull in opposite directions. Winter is the postcard version — the Yubatake steaming hard against the cold, snow on the rooftops, and that singular pleasure of a scalding outdoor bath while flakes drift down. It's also when the highland setting earns its keep. Summer flips the appeal: while Tokyo bakes, Kusatsu's altitude keeps it noticeably cooler, making it a genuine mountain escape rather than a sweaty slog. Specific temperatures and snowfall figures swing year to year — I'd rather not pin down numbers that don't hold — but the qualitative picture is reliable: come in winter for the atmosphere and the snow-bath drama, come in summer to get out of the heat. Spring and autumn are quieter shoulder seasons with their own appeal. Whatever you choose, weekends and long holidays draw crowds; a weekday visit is calmer in every season.
Where to Stay — Mid-Range Ryokan in Kusatsu
Kusatsu is at its best when you don't have to leave at sunset, and the town has a deep bench of mid-range ryokan within walking distance of the Yubatake — many of them long-established inns running their own source-fed baths. A good mid-range ryokan here typically includes a multi-course dinner, breakfast, and access to private or semi-private baths, so you can soak late and again at dawn without ever stepping outside. Staying within a few minutes' walk of the Yubatake is the move: it puts the night lighting and the empty early-morning square on your doorstep.
If you'd like to start with a shortlist of well-reviewed mid-range inns near the Yubatake, you can browse Kusatsu Onsen ryokan here.
A Quieter Kusatsu — Tips for Avoiding the Crowds
Kusatsu can feel busy — it's a famous town, and the day-trip buses unload a lot of people into a small square. But the crowds are predictable, which means they're avoidable.
The single best trick is timing. The Yubatake is quietest just after dawn, before the day-trippers arrive and after the overnight guests have gone back to their inns for breakfast. I've stood at the railing at first light with the whole steaming field to myself and maybe one other early riser. Walk the public bathhouses in that early window too, when the visitor-accessible ones are calmest, and save Sainokawara's big open-air bath for either right at opening or late in its hours rather than the midday rush. Mid-afternoon, when the Yumomi shows and the tour groups overlap, is the busiest stretch in the center — that's a good time to slip down a side lane, find a footbath, and let the square thin out. And if your dates are flexible, a weekday beats a weekend or a national holiday by a wide margin. None of this requires special access; it just requires being awake when most visitors aren't. (Opening hours vary by bathhouse and can change seasonally — confirm them so your early-morning plan actually lines up.)
Frequently Asked Questions
Is Kusatsu Onsen worth visiting?
Yes — and not just on reputation. Kusatsu pairs a genuinely striking centerpiece (the Yubatake) with real, untreated source water and a walkable town you can explore on foot. It's the town Japanese travelers most consistently want to return to, which tells you something the rankings can't fake.
Can you visit Kusatsu as a day trip from Tokyo?
You can, but it's tight. With travel times of roughly 3 to 4 hours in each direction, a day trip means most of your day is spent in transit, and you'll miss the night lighting and the quiet early morning — the two times the town is at its best. If you only have a day it's still worth it; if you can spare a night, take it.
Are the baths in Kusatsu free to enter?
Some are, but with a catch. Several communal bathhouses are free, yet many are reserved for local residents — the visitor-accessible free ones are a shorter list (Shirahata-no-yu, Chiyo-no-yu, and Jizo-no-yu). The larger open-air baths like Sainokawara are paid (¥800 for adults). The town's footbaths are free for everyone.
Is Kusatsu Onsen tattoo-friendly?
Policies vary by facility and can change, so this is one to confirm directly. Whether a specific bath, including Sainokawara, admits visitors with tattoos isn't something the facilities spell out consistently, so check the individual facility's official information before you go rather than relying on secondhand lists.
How long should you stay in Kusatsu?
One night is the sweet spot for most travelers. It gets you the lit Yubatake at night, the empty square at dawn, an evening soak, and a Yumomi show without rushing. Two nights suits anyone who wants to bath-hop slowly or use Kusatsu as a cool-weather mountain base.
What's the best season to visit Kusatsu?
Winter for snow and steaming outdoor baths; summer for cool highland air while the cities swelter. Both are excellent for different reasons. Specific climate figures swing year to year, but you won't go wrong in either season — just avoid weekends and holidays if you want it quiet.
My Honest Take
Kusatsu earns its loyalty ranking. It's not a delicate, hushed kind of onsen town — it's loud with steam and sulfur and the slap of yumomi paddles — but that's exactly what makes it stick with you. Do it as a day trip and you'll see why it's famous. Stay the night and you'll understand why people keep going back: the lit Yubatake after dinner, the silent square at dawn, that first scalding soak before anyone else is awake. Book a mid-range ryokan within walking distance of the square, give yourself one full evening and one slow morning, and let the town do the rest.
Ready to plan it? Check availability for Kusatsu Onsen ryokan and pick your night by the Yubatake.
Image credits: Cover — the Yubatake at Kusatsu Onsen by day, by Aspere (CC0). In-text images are credited in their captions. All images via Wikimedia Commons.