Nakabusa Onsen

Nakabusa Onsen is a mountain hot spring set right at the Mt. Tsubakuro trailhead (elevation about 1,450m) in the Northern Alps, in Azumino City, Nagano Prefecture. It is a secluded spring blessed with abundant natural hot water, and at the same time the gateway to Mt. Tsubakuro and the Omote-Ginza traverse, so many hikers stop here on the way up and back down. The trailhead is only about 30 seconds from the bus stop and car park, making it truly a hot spring you can soak in right before or after your climb.

This page is a trailhead hub that gathers everything on one page, useful both for those coming to Nakabusa Onsen itself and for hikers heading to Mt. Tsubakuro or Omote-Ginza: how to get there (the Nakabusa Line bus and the night bus), parking, day-use bathing and facilities, and whether a day hike is realistic.

*Timetable last checked: July 4, 2026

1. What is Nakabusa Onsen

Nakabusa Onsen is a single-inn hot spring at the Mt. Tsubakuro trailhead in the Northern Alps, at an elevation of about 1,450m. It sits deep in the mountains of Azumino City, Nagano Prefecture, and is linked by bus from Hotaka Station on the JR Oito Line. Because the trailhead is right outside the grounds, it is used both as a base for day hikes and as a place to stay the night before and set off at dawn. The first step onto the Omote-Ginza traverse (the ridge route from Mt. Tsubakuro over Mt. Otensho to Mt. Yari) also begins here at Nakabusa Onsen.

2. Mountains you can climb from here (Mt. Tsubakuro / Omote-Ginza)

Nakabusa Onsen is the main gateway to Mt. Tsubakuro, a much-loved peak known as an introduction to the Northern Alps. The usual route climbs the Kassen Ridge, passes Enzan-sō, and continues to the summit of Mt. Tsubakuro.

Mt. Tsubakuro is also the starting point of the popular Omote-Ginza traverse, which runs from Mt. Tsubakuro over Mt. Otensho to Mt. Yari. Walking Omote-Ginza requires overnight stays in mountain huts and cannot be done as a day trip. A good approach is to climb Mt. Tsubakuro as a round trip first, then move on to Omote-Ginza once you are used to the terrain.

3. [Outbound] Getting to Nakabusa Onsen

There are two main ways to reach Nakabusa Onsen: the Nakabusa Line shared bus from JR Hotaka Station (during the day) and the “Mainichi Alpen-go” night bus from Tokyo (arriving at dawn).

Bus TimetableHotaka Station → Nakabusa Onsen

Board the “Nakabusa Line shared bus” operated by Nan-an Taxi in front of Hotaka Station and get off at Nakabusa Onsen. The ride takes 55 minutes and costs ¥1,500 one way. It runs on scheduled days from April 24 to November 3, 2026, and reservations are required. Some departures are cancelled depending on the day, so always check Nan-an Taxi’s official service calendar before you travel.

Reference : Nan-an Taxi scheduled bus to Nakabusa Onsen (service calendar)

Night BusTakebashi → Mt. Tsubakuro Trailhead / Nakabusa Onsen

From the Tokyo area you can arrive at dawn on the overnight “Mainichi Alpen-go” (reservation required, seasonal service). It departs “Takebashi Station” (Mainichi Shimbun west entrance) on the Tokyo Metro Tozai Line at 23:00 and reaches the Mt. Tsubakuro trailhead / Nakabusa Onsen around 5:30 to 6:00 the next morning. The outbound fare is ¥11,000 to 17,000 (varies by season and seat).

4. [Return] Getting back from Nakabusa Onsen

Bus TimetableNakabusa Onsen → Hotaka Station

For the return trip you again use Nan-an Taxi’s Nakabusa Line shared bus. Board at Nakabusa Onsen and get off at Hotaka Station; the ride takes 55 minutes and costs ¥1,500 one way. The number of departures also changes by day, so it is best to check the service calendar and reserve in advance.

Reference : Nan-an Taxi scheduled bus to Nakabusa Onsen (service calendar)

Night BusNakabusa Onsen → Shinjuku / Tokyo

To return toward Tokyo you can also use the “Mainichi Alpen-go” (reservation required, seasonal service). It leaves Nakabusa Onsen at 14:00, calls at Ariake-sō (14:05) and Chōgatake Onsen Holiday-yu (15:10), and arrives at Shinjuku Station West Exit around 19:45 and in front of Tokyo Station around 20:15. The return fare is a flat ¥8,000.

5. From Nakabusa Onsen to the trailhead

Nakabusa Onsen is itself the Mt. Tsubakuro trailhead. From the bus stop and car park to the trailhead (elevation about 1,450m) is only about 30 seconds, with no real walking section in between. From here you climb the steep Kassen Ridge toward Enzan-sō and Mt. Tsubakuro. Being able to start climbing the moment you arrive, with little wasted time, is a major advantage of starting from Nakabusa Onsen.

6. Hot spring, parking, facilities and staying overnight

Day-use bathing: The open-air bath “Yubara-no-yu” is open for day visitors. Adults ¥950, open 9:30 to 17:00 (last entry 16:00). You can wash off the sweat before or after your hike.

Lodging: There are accommodations including Shōsen-kaku, from ¥15,000 per night with two meals, or ¥10,050 for a shared room without meals. Staying the night before lets you set off comfortably at dawn.

Parking: If you come by car, use the paid Nakabusa Trailhead First Car Park (managed by Times) among others. There is also the Nakabusa Onsen car park for hikers (reservation required, ¥5,000 per vehicle) as well as free parking. Toilets are provided.

Season: It normally operates from late April to early November (in winter it runs on a separate basis, and access then requires about four hours of walking).

7. The last bus back and whether a day hike works

The last Nakabusa Line shared bus back departs Nakabusa Onsen at 16:15 and arrives at Hotaka Station at 17:10. Whether you can make this last departure is the deciding factor for a day hike using public transport.

That said, the Kassen Ridge on Mt. Tsubakuro takes a long time to walk (about 9 hours round trip), so a day hike suits strong walkers. Even taking an early bus does not leave much margin, so an overnight stay at Enzan-sō is generally the safer plan. Rather than insisting on a day hike, stay the night before at Nakabusa Onsen and set off at dawn, or plan a hut stay, so you can climb with time to spare.

Photo by Alpsdake