Things to Do in Kusatsu Onsen, Now That 4 Million People Come Every Year

Step off the bus and the sulfur finds you first — before the steam, before the wooden chutes cooling near-boiling water in the middle of town. This is Kusatsu, about three hours and ¥6,300 from Tokyo, and it now draws a crowd to match its name. In fiscal 2024 the town logged 4.019 million arrivals — up 8.6% on the year before. That's the first time these steaming stone channels have crossed the four-million line.

That number should change how you read every list of things to do in Kusatsu Onsen, including this one. The attractions haven't moved: the Yubatake still cools its water through wooden chutes, the acidic springs still announce themselves from the bus terminal. What record demand rewrites is timing. Catch the town quiet and a photo stop becomes the best onsen trip in Japan.

Time your day around four million visitors

Run the numbers and the day plans itself. Kusatsu is no Tokyo day trip — the fastest rail route is close to three hours each way — yet much of that record crowd treats it like one, rolling in late morning and clearing out by late afternoon. So the Yubatake perimeter and the manju street jam from roughly 10:00 to 15:00, worst on October weekends when foliage piles onto onsen season and parking fills by mid-morning. We checked the daily rhythm: before 8:00 and after 21:00, those same streets are close to empty — just steam and sulfur in the cold air.

There's a quieter trap, and it's dinner. Because ryokan guests eat in, most independent restaurants serve lunch and close between roughly 15:00 and 18:00. Day-trippers banking on a late meal and overnighters on no-meal plans both get caught out. The town assumes you're eating at your inn — book dinner there and stop fighting it.

Sanpo tip: on a no-meal plan, reserve a lunch table a day ahead — noon fills the same kitchens that shut by 15:00.

Let the timetable pick your route

The workhorse route is the JR Limited Express Kusatsu–Shima from Ueno to Naganohara-Kusatsuguchi — about 2 hours 20 minutes, ¥5,770. A 25-minute JR bus (¥710 IC) carries you the rest of the climb to the Kusatsu Onsen terminal. Call it three hours and ¥6,300–6,500 one way. Here's the catch: only two or three limited-express departures run a day, so pull up the timetable before you book anything else — the JR East Pass (Nagano–Niigata area) covers the fare, but it can't conjure a fourth train.

Pinching yen? The direct JR highway bus from Shinjuku runs around four hours and roughly ¥3,500–4,500 depending on the date — slower, but one seat the whole way with your bags beside you. A third option, the Karuizawa shinkansen plus a local bus, can be quicker door-to-door, but that bus is thin on departures — a fallback, not a plan. And mind the altitude: at roughly 1,200 m, even early-autumn evenings edge toward freezing, so pack a warm layer.

Sanpo tip: book your limited-express seat the moment your dates firm up — with two or three trains a day, they sell out on peak weekends.

Soak the baths in the right order

Kusatsu's self-flowing hot-spring yield — over 32,300 liters a minute, the largest in Japan — pours out strongly acidic, around pH 2 at the Yubatake source. It's genuinely harsh: it stings shaving nicks, strips the oil from your skin, and surfaces close to scalding. So sequence matters — climb the temperatures, don't jump them.

Sanpo tip: if you're doing all three town-run baths, the discounted san-yu combo pass beats paying each gate.

• Otaki-no-yu (¥1,200): start here. Its awase-yu — a wooden stair of four pools rising in temperature — is the old way to acclimatize
• Sainokawara open-air bath (¥800): roughly 500 m², among Japan's largest rotenburo. The 10-minute walk up passes green-tinted pools steaming straight out of bare rock
• Yumomi show at Netsu-no-yu: a 20-minute paddle-and-folk-song ritual that cools 50°C+ water without watering it down. Listed at ¥600, but prices were revised in September 2025 — confirm on the day
• The free jimoto baths (Shirahata-no-yu, Chiyo-no-yu, Jizo-no-yu): no showers, scalding water, strict etiquette — advanced material for a second visit
• Rinse off afterward if your skin runs sensitive — an exception to the usual onsen rule — and cap it at two or three soaks a day

Eat where the locals eat

First, walk past the free-sample manju hawkers ringing the Yubatake — the tasting is a soft-pressure sales funnel, not a favor. Buy from the shopfronts instead. Matsumura Manju is the one locals point to, its thin-skinned, restrained-sweetness buns going for around ¥120–150 apiece. It also holds the highest verified rating in town — 4.4★ across 392 Google reviews.

For lunch, take your pick. Tonka near the bus terminal plates a jumbo rosu-katsu teishoku with free rice and cabbage refills (4.3★, 576 reviews). Joshu Jigona Udon Matsumoto on Sainokawara-dori pulls flat himokawa udon from 100% Gunma wheat, and the queue turns fast (4.2★, 560 reviews).

Soba Kanai, a hush of a second-floor room near the Yubatake, sends out duck dipping soba around ¥1,300 (4.2★, 165 reviews). Mikuniya, the big name, leads on volume past 1,000 reviews but sits at 3.9★ — the gripes point at peak-hour queues, not the food. Whichever you choose, eat your main meal at lunch: the kitchens close early.

Things to do in Kusatsu Onsen beyond the baths

Sainokawara Park is free and never closes: hot water seeps up through the valley floor, footbaths line the path, and by late October it's the town's finest foliage walk. Keep climbing and you reach the Yoshigadaira wetlands, a Ramsar-registered highland marsh whose ponds mirror the autumn color from late September to mid-October — bring proper gear, because the weather turns fast above 1,800 m. One honest caveat hangs over the famous Yugama crater lake: the volcanic alert only eased to Level 1 in May 2026, and though Route 292 has reopened, on-foot access near the rim stays restricted. Treat the turquoise water as drive-through scenery, check the current status before you go, and remember the road shuts entirely each winter.

Own the quiet hours

Here's the contrarian read of that four-million figure: record demand hasn't spoiled Kusatsu — it's made the off-hours precious. The whole crowd packs into a five-hour midday window, so an overnight guest who walks the Yubatake before 8:00 — steam heaviest in the cold air, the Kengo Kuma-designed stone terrace empty, sulfur sharp in the nose — sees a town most of those four million never meet.

Call it a hunch, but we suspect the gap between the daytime town and the 7 a.m. town only widens as arrivals climb. The list of things to do in Kusatsu Onsen is short and stable; the real skill is doing them while the town still belongs to the people sleeping in it. Book the night.