Gunma is one of the few places near Tokyo where you can link three very different hot-spring towns and a night under canvas in a single weekend without spending the whole time on the expressway. This is a planning itinerary, not a trip report: a realistic two-day loop with time blocks, approximate driving legs, budget ranges, the bathing rules that trip campers up, and the mistakes that most often break a plan like this. Times and prices are typical, not guaranteed, so treat every number as something to confirm.

The Route at a Glance

The loop is Tokyo → Ikaho → Kusatsu (camp) → Shima → Tokyo, about 400-450 km in total, with roughly 6-7 hours of driving split over two days.

  • Ikaho Onsen (伊香保温泉): a compact town built around a long stone staircase, with two types of water: the iron-rich, brownish "kogane-no-yu" (黄金の湯) and the clear "shirogane-no-yu" (白銀の湯). Easy to reach from the Kan-Etsu Expressway, so it works as the morning stop.
  • Kusatsu Onsen (草津温泉): at roughly 1,200 m, one of Japan's best-known hot springs, centred on the steaming Yubatake (湯畑). The water is strongly acidic, around pH 2. This is the camping night: the altitude makes summer nights cool and the town gives you several day-use baths within a short distance.
  • Shima Onsen (四万温泉): a quieter valley town with an old-fashioned main street and the blue waters of Okushima Lake (奥四万湖) above it. A gentle last stop before the drive home.

Why this order? Ikaho is closest to the expressway, so you start without a long mountain drive. Kusatsu needs the most time and is the best place to camp. Shima sits on the way back toward the Kan-Etsu, so the return leg is short. A popular variant swaps Shima for Minakami and Takaragawa Onsen (宝川温泉), covered below.

This plan assumes a car and the green season, roughly May to October. For the wider regional picture, see the Kanto camping guide.

Day 1: Ikaho in the Morning, Kusatsu by Afternoon

Times assume a Saturday start from central Tokyo and normal traffic. Add 20-30% to any navigation estimate for weekend traffic and mountain roads.

  1. 07:00 - Leave Tokyo via the Nerima IC onto the Kan-Etsu Expressway. Leaving early is the single biggest time saver; outbound traffic builds quickly after 08:00 on weekends.
  2. Around 08:45 - Shibukawa-Ikaho IC. From here to Ikaho is roughly 20-30 minutes uphill.
  3. 09:15-11:00 - Ikaho. Walk the stone steps (石段街) before the day-trippers arrive, continue to Ikaho Shrine at the top, and on to the source area if you have time. Bathe here only if you want to: a short soak at a public bath such as Ishidan-no-yu (石段の湯) or the open-air Ikaho Rotenburo (伊香保露天風呂) works, but keep it brief because the main bath of the day is in Kusatsu. Opening hours for both differ by season and closing days.
  4. 11:00-12:00 - Early lunch in Ikaho or on the way.
  5. 12:00-13:45 - Drive to Kusatsu, roughly 1.5-2 hours via the Nakanojo and Naganohara area. Buy food and ice in the lower valley. Shopping options thin out up the mountain, and town-centre parking in Kusatsu fills on weekends.
  6. 14:00 - Campsite check-in. Many campgrounds check in from around 13:00-14:00; confirm the exact window and the latest arrival time when you book. Find candidate campgrounds on the map and book ahead for weekends and holidays.
  7. 14:30-16:00 - Pitch and set up. At 1,200 m, set the tent for wind and expect a cold night even in August.
  8. 16:30-18:00 - Bath in Kusatsu. The large Sainokawara Open-Air Bath (西の河原露天風呂) and Otaki-no-yu (大滝乃湯) are the usual choices for visitors. Bathing before dinner means you are clean while the facilities are open; last entry at many day-use baths is 30-60 minutes before closing.
  9. 18:30 - Dinner at camp. A gas stove keeps you cleaner than a wood fire if you want to stay presentable for the evening.
  10. After dinner - Yubatake at night, if your campsite is within walking distance or you have not been drinking. If you have had any alcohol, you do not drive, not even the few minutes into town.

Day 2: Kusatsu Morning, Shima Afternoon, Home

  1. 06:00 - Wake and dry the tent. Morning dew at altitude is heavy; drying the fly for 30 minutes saves a wet pack-up at home.
  2. 08:30-09:30 - Pack and check out. Check-out is commonly between 10:00 and 11:00.
  3. 09:30-10:30 - Yubatake in daylight. Optionally watch the yumomi (湯もみ) water-stirring show at Netsunoyu (熱乃湯), which runs several times a day for a fee.
  4. 10:30-12:00 - Drive to Shima, roughly 1-1.5 hours back down through Nakanojo.
  5. 12:00-13:30 - Lunch and a walk. The old street, and Okushima Lake a short drive further up the valley.
  6. 13:30-14:30 - Bath in Shima. The village has small communal baths and several inns that accept day-use bathers; the historic Sekizenkan (積善館) is the best known, but whether day-use is offered, at what times and whether a reservation is needed changes, so check before you go.
  7. 15:00 - Leave Shima. About an hour to the Shibukawa-Ikaho IC.
  8. 18:00-19:30 - Back in Tokyo. The upbound Kan-Etsu is often congested on Sunday and holiday afternoons. Leaving Shima by 14:00 or waiting until after dinner both beat sitting in the jam.

Without a car

The loop can be done by public transport, but camping becomes harder because you carry everything and the campgrounds are rarely next to a bus stop.

  • Kusatsu: the limited express "Kusatsu-Shima" (草津・四万) from Ueno to Naganohara-Kusatsuguchi takes roughly 2.5 hours, then a JR bus of around 25 minutes to Kusatsu Onsen bus terminal. Highway buses also run from Tokyo.
  • Ikaho: bus from JR Shibukawa Station, roughly 25 minutes.
  • Shima: bus from JR Nakanojo Station, roughly 40 minutes.

Frequencies are low on some routes, so build the plan around the timetable, not the other way round. Without a car, a campground that rents gear or a cabin near Kusatsu is the realistic choice.

Budget Ranges

These are rough ranges for two people sharing a car, to help you size the trip; check current prices before you commit.

  • Expressway tolls: roughly ¥6,000-¥8,000 for the round trip between Tokyo and Shibukawa-Ikaho, depending on ETC discounts and time of day. NEXCO East's route search gives the exact figure.
  • Fuel: roughly ¥5,000-¥8,000 for 400-450 km, depending on the car.
  • Rental car (if needed): roughly ¥15,000-¥30,000 for two days, more in peak season or for a larger car.
  • Campsite: roughly ¥3,000-¥7,000 per site per night, plus possible per-person or car fees.
  • Day-use baths: from a few hundred yen at small public baths to around ¥1,000-¥2,000 at larger facilities and inns, per person, per bath.
  • Food and supplies: depends entirely on your choices.

Adding these up, a pair with their own car and gear typically lands around ¥17,000-¥35,000 before food; add the rental if you need one.

Onsen Rules That Matter for Campers

General etiquette is in our onsen etiquette for campers; these are the points that come up specifically on this route.

  • Wash before entering. Use the washing area, or at small communal baths without showers, pour water over yourself from the basin (kakeyu, かけ湯) before stepping in. After a night at camp this matters more than usual: woodsmoke in hair and soot on hands go into the shared water if you skip it.
  • Leave camp clothes in the car. Change into clean clothes for the bath visit, and leave muddy boots and the smoky jacket behind. Bring a small towel and a bath towel; many baths sell or rent them, but small communal baths do not.
  • Towels stay out of the water. Fold the small towel on your head or leave it at the edge. Tie long hair up. No swimsuits in standard baths.
  • Tattoos: policies vary from bath to bath. Some accept them, some accept small ones covered with a sticker, some refuse entry. Check each facility's website, and do not assume one town has one rule.
  • Kusatsu's water is strongly acidic. It stings cuts, scratches and chapped hands, and irritates eyes. People with sensitive skin often rinse with fresh water afterwards. Remove silver and other metal jewellery, which sulfurous water can tarnish.
  • Free communal baths are not attractions. Kusatsu and Shima have small free or donation-based baths maintained by locals. Some are open to visitors and some are for residents only; follow the sign, keep it short and quiet, and leave it as clean as you found it.
  • Know the hours. Day-use bathing (日帰り入浴) usually has fixed hours and an earlier last-entry time, and inns may stop accepting day visitors when busy. Do not plan your only bath of the day for 20:30.
  • No alcohol before bathing, drink water, and keep the first soak short in very hot water.

Seasons and Roads

  • Green season (May-October): the easiest window. Even in midsummer, Kusatsu nights can drop well below Tokyo temperatures, so a sleeping bag rated for cool nights is wise; see the three-season sleep system guide.
  • Autumn: foliage is excellent but nights at 1,200 m approach freezing by late October and November, and campgrounds may close for the season.
  • Winter (roughly November-April): winter tyres or chains are needed around Kusatsu, and snow can affect roads to Shima and Ikaho too. If you hire a car, ask for studless winter tyres. Camping in winter is a different trip; read winter camping in Japan first.
  • Shiga-Kusatsu Kogen Route: National Route 292 over the pass to Shiga Kogen in Nagano is closed in winter, typically from around mid-November to late April. Separately, sections near Mt. Kusatsu-Shirane have had restrictions linked to volcanic activity, such as no-stopping zones or night closures. This loop does not need the pass, but if you want to add it, check the current status.
  • Volcano and weather: check volcanic warnings and forecasts on the Japan Meteorological Agency site, and avoid exposed high ground in thunderstorms.

What Commonly Goes Wrong

  • Trusting navigation times. Mountain roads and weekend traffic routinely add 20-30%. A plan with no slack falls apart at the first queue.
  • Missing check-in or last entry. Campsite reception and day-use baths close earlier than you think. A late start in Tokyo cascades into a missed bath.
  • Assuming the communal bath is open to you. Respect "residents only" signs and have a paid bath as the plan.
  • Planning the Shiga-Kusatsu pass in winter or spring. It is often still closed in early spring.
  • Summer tyres in shoulder season. Early snow and frost at altitude are not unusual in November and April.
  • Underdressing for the night. 1,200 m feels very different from Tokyo, especially in spring and autumn.
  • Drinking at camp, then driving to the bath. Japan's drink-driving rules are strict; bathe first, drink later.
  • Not booking. Weekend and holiday sites in Kusatsu fill early. Our guide to booking paid campsites walks through the process.

Variant: Minakami and Takaragawa

If you would rather pair camping with river scenery, swap Kusatsu and Shima for Minakami (みなかみ), reached via the Minakami IC on the Kan-Etsu, roughly 2-2.5 hours from Tokyo. The Tone River valley has many campgrounds, and Takaragawa Onsen's riverside open-air baths are among Gunma's best known. Its rules on mixed areas and bathing garments have changed over time, so read the current information before you go. The ordering becomes: Ikaho in the morning, Minakami camp, Takaragawa or a Minakami day-use bath on day two, then home on the same expressway.

Wrap-Up

Start early, put the hardest leg on day one, camp at altitude with warm gear, bathe before you drink, and keep a paid bath as the backbone of each day. Treat every time and price here as a starting estimate.

Bath hours, road closures, campsite seasons and bus timetables change: confirm with the official tourism sites, operators and road information before you travel.