Mt. Akaiwa

Mount Akaiwa (Akaiwadake, 2,769 m) stands in the Jonen range of the southern North Alps, in Nagano. One of Japan’s 100 Highest Mountains, it rises between Mount Otensho and Mount Nishi on the “Omote-Ginza” traverse that links Mount Tsubakuro and Mount Yari. Because the trail bypasses the summit on its east side, few hikers actually stand on top — a quiet peak looking out at the Yari–Hotaka ridgeline.

*Timetable last checked: 2026-06-14

How to access the trailheads

1. [Outbound] Hotaka Station → Nakabusa Onsen (Tsubakuro trailhead)
2. [Outbound] Takebashi Station → Nakabusa Onsen (night bus)
3. [Return] Nakabusa Onsen → Hotaka Station

1. [Outbound] Hotaka Station → Nakabusa Onsen (Tsubakuro trailhead)

Trailhead = the Tsubakuro trailhead at Nakabusa Onsen (approx. 1,450 m).
From in front of JR Oito Line Hotaka Station, take the Nan-an Taxi “Nakabusa Onsen bus” and get off at the Nakabusa Onsen terminus, where the Tsubakuro trailhead is.

Ride time: approx. 55 min
Fare: ¥1,500
Operating period: set days from late April to early November

The number of services differs by A / B / C service-day category. A-days include the early 5:15 service; on C-days the morning services are suspended and the first bus is 11:10. Always check which category applies on your day with the Nan-an Taxi service-day calendar.

Bus TimetableHotaka Station → Nakabusa Onsen (A-days)

Bus TimetableHotaka Station → Nakabusa Onsen (B-days)

Bus TimetableHotaka Station → Nakabusa Onsen (C-days)

Reference: [Nan-an Taxi Nakabusa Onsen bus (service-day calendar)]

2. [Outbound] Takebashi Station → Nakabusa Onsen (night bus)

From the Tokyo area, the Mainichi Alpen-go “Tsubakuro / Jonen / Cho” night bus is available. Board at Takebashi Station (Tozai subway line, Mainichi Newspaper west entrance) and get off at the Tsubakuro trailhead, Nakabusa Onsen (reservation-only).

Takebashi Stn. dep. 23:00 (gather 22:45) → Tsubakuro trailhead, Nakabusa Onsen arr. around 5:30–6:00
Ride time: approx. 6–7 hours (overnight)
Fare: from ¥8,800 (varies by season and seat; reservation required)

Details: [Mainichi Alpen-go Tsubakuro / Jonen / Cho]

3. [Return] Nakabusa Onsen → Hotaka Station

From Nakabusa Onsen, take the Nan-an Taxi “Hotaka Station bus” and get off at Hotaka Station. The Omote-Ginza traverse takes time, so allow margin for the last bus. For the Tokyo area, you can also return from Nakabusa Onsen to Shinjuku on the Mainichi Alpen-go (reservation-only).

Ride time: approx. 55 min
Fare: ¥1,500
Operating period: set days from late April to early November

Bus TimetableNakabusa Onsen → Hotaka Station (A / B-days)

Bus TimetableNakabusa Onsen → Hotaka Station (C-days)

Reference: [Nan-an Taxi Nakabusa Onsen bus (service-day calendar)]

4. Climbing route, the crux and estimated trail times of Mount Akaiwa

The starting point for Mount Akaiwa is Nakabusa Onsen. Climb the Kassen ridge to Mount Tsubakuro and Enzanso, follow the Omote-Ginza traverse to Mount Otensho (Daitenso, Daitensho Hütte), and take the Kisaku New Trail to Mount Akaiwa.

● Omote-Ginza traverse route
Nakabusa Onsen → Kassen ridge → Enzanso → Odori-no-kashira → Kiridoshi-iwa → Daitenso (Mount Otensho) → Daitensho Hütte → Mount Akaiwa → Hütte Nishidake → (on to Mount Yari via the Higashi-kama ridge). The Kisaku New Trail was opened in 1921 by the hunter Kisaku Kobayashi; Kiridoshi-iwa has chains and an iron ladder, and the ground drops away near the Kisaku relief.

● The summit of Mount Akaiwa (for experienced climbers, at your own risk)
The Omote-Ginza trail passes around the east side without crossing the summit. There is no official trail to the triangulation-point summit: it means climbing straight up a loose, crumbling slope from the southeast, with about 10 m of creeping-pine scrambling just below the top. The risk of rockfall and slips is high; stay away in bad weather.

Standard trail times for the main sections (summer / snow-free guide)

• Nakabusa Onsen → Kassen ridge → Enzanso: approx. 5 hours (ascent, elevation gain approx. 1,250 m)
• Enzanso → Odori-no-kashira → Daitenso (Mount Otensho): approx. 3 hours
• Daitenso → Daitensho Hütte → Mount Akaiwa → Hütte Nishidake: approx. 2 h 30 min

The view
From the ridge around Mount Akaiwa, the sharp rock spires of Mount Yari and the Hotaka range loom close at hand, with Mount Tsubakuro and Mount Otensho and the Tateyama and Ushiro-Tateyama ranges in view. Because the trail bypasses the summit, few hikers stand on top and you can enjoy the grand panorama in quiet.

Recommended plan (2 nights / 3 days, Omote-Ginza traverse)

• Day 1: Hotaka Station → Nakabusa Onsen → Kassen ridge → Enzanso (overnight)
• Day 2: Enzanso → Mount Otensho → Mount Akaiwa → Hütte Nishidake or Daitensho Hütte (overnight)
• Day 3: Descend the way you came to Nakabusa Onsen, or traverse via the Higashi-kama ridge to Mount Yari and Kamikochi

One or two nights on the mountain are assumed; a day trip is impossible.

5. Huts and emergency contacts

Omote-Ginza huts (all require reservation)

• Enzanso (just below Mount Tsubakuro): the base at the start of the Omote-Ginza. Reservations 0263-32-1535
• Daitenso / Daitensho Hütte (below Mount Otensho / on the ridge): the nearest lodging to Mount Akaiwa. Reservations 0263-83-5810
• Hütte Nishidake (below Mount Nishi): a base on the Mount Yari side of Mount Akaiwa, with an adjoining tent site.

There are almost no water sources on the ridge; buy drinking water at the huts. Confirm 2026 opening periods and reservation methods with each official source.

Emergency contacts

• Nagano Pref. Police, mountain rescue / Omachi Police Station: 0261-22-0110
• Azumino City Office: 0263-71-2000
• In an accident or distress: 110 (police) / 119 (fire & rescue). Always file a climbing plan.

Photo by Alpsdake