Mt. Komatsu

Mt. Komatsu (Komatsumine, 2752 m) rises on the border of Yamanashi and Nagano prefectures in the northern Southern Alps and is one of Japan’s 100 Highest Mountains.
A forepeak of Mt. Kaikomagatake, it is the key junction where the Futagoyama route and the Sensui-toge route from Kitazawa-toge meet on the way up Mt. Kaikomagatake. From its summit the white granite mass of Mt. Kaikoma and Mt. Marishiten loom close at hand, with a wide view of Mt. Senjo, Mt. Nokogiri, Mt. Kita and the Hoo Sanzan. The usual approach is a loop from Kitazawa-toge over Futagoyama and Sensui-toge to Komatsumine, often continuing on to Mt. Kaikomagatake.
The gateway is Kitazawa-toge. The South Alps forest-road bus from Todai Park on the Ina side (Nagano) reaches Kitazawa-toge, so it can be approached by public transport.

Komatsumine lies partway up the climb from Kitazawa-toge to Mt. Kaikomagatake, and the popular plan is a loop up via Futagoyama and down via Sensui-toge. Whether your goal is Komatsumine alone or continuing to Mt. Kaikomagatake, this loop is the basis. The season is early June to early November, while the forest-road bus runs and the huts are open; outside it, snow and ice make the route unsuitable for general hikers.

*Information last checked: June 14, 2026

Getting to the trailhead

1. [Outbound] Chino Station → Todai Park → Kitazawa-toge
2. [Return] Kitazawa-toge → Todai Park → Chino Station

1. [Outbound] Chino Station → Todai Park → Kitazawa-toge

From Chino Station on the JR Chuo Main Line, take the JR Bus Kanto “South Alps Geoliner” to Todai Park (formerly Senryuso), then transfer to the South Alps forest-road bus (Queen Line) and get off at Kitazawa-toge. There is also a route from Ina-shi Station (Ina bus terminal) on the “Morning Geoliner” (Saturdays only) to Todai Park. By car it is about 40 minutes from the Ina IC on the Chuo Expressway to Todai Park.

Timetable 1: Chino Station → Todai Park (South Alps Geoliner)

Timetable 2: Todai Park → Kitazawa-toge (South Alps forest-road bus)

On days the 5:45 bus runs, the 6:30 service is suspended. Catching the first bus allows a day trip taking in Komatsumine and Mt. Kaikomagatake. There is a hut (Komorebi Sanso) at Kitazawa-toge, so you can also stay the night before and start early.

Reference: [Ina City — South Alps forest-road bus timetable]

2. [Return] Kitazawa-toge → Todai Park → Chino Station

After descending, take the South Alps forest-road bus from Kitazawa-toge down to Todai Park, then return toward Chino Station or Ina by Geoliner (or private car/taxi). The forest-road bus from Kitazawa-toge is also seasonal with limited services, so check the time of the last bus on the Todai Park / Ina City official information and allow plenty of time to descend. The descent from Komatsumine is long via Futagoyama, while the Sensui-toge route drops through forest from Sensui-toge past Sensui-goya to Kitazawa-toge.

Reference: [Ina City — South Alps forest-road bus timetable]

Climbing routes and trail times

Route 1: Futagoyama–Sensui-toge loop (from Kitazawa-toge, day trip)
Kitazawa-toge (2030 m) → Futagoyama (2649 m, about 1 hour 40 minutes) → Komatsumine (2752 m, about 1 hour). Descend Komatsumine → Sensui-toge → Sensui-goya → Kitazawa Choei-goya → Kitazawa-toge (about 2 hours 30 minutes to 3 hours), making a loop of about 5 to 6 hours in total. It can also be walked the other way (climbing from Sensui-toge). The Futagoyama route is a long climb from forest into creeping pine, while the Sensui-toge route crosses the boulder-strewn Sensui-toge — a varied trail.

Route 2: continuing to Mt. Kaikomagatake
From Komatsumine, continue past Roppo-ishi to Mt. Kaikomagatake (2967 m). Beyond Roppo-ishi the trail splits into a direct granite climb (rocky) and a path skirting Mt. Marishiten; the direct line is a rocky ridge with good holds but exposed. Komatsumine to Mt. Kaikomagatake is about 1 hour 30 minutes one way. For a day trip, take the first forest-road bus to Kitazawa-toge, make a return trip to Mt. Kaikomagatake via Komatsumine, and descend on the last bus.

Mountain huts and lodging

Komorebi Sanso (Kitazawa-toge, 2030 m): the hut at the Kitazawa-toge trailhead, a base for staying the night before and starting early. Kitazawa Choei-goya (about 10 minutes’ walk from Kitazawa-toge) has a tent site and is the start of the Sensui-toge route. Sensui-goya is just before Sensui-toge and useful as a staging point toward Komatsumine and Mt. Kaikoma. All open in summer and require reservations; check opening periods on each official website or by phone.

Water: water can be taken at Kitazawa-toge, Kitazawa Choei-goya and Sensui-goya. There is none on the ridge, so carry plenty.

Hazards, gear and best season

Difficulty: the trail to Komatsumine has no chains and can be done as a day trip from Kitazawa-toge, but the Futagoyama route has a large elevation gain and a long climb that demands stamina. Continuing to Mt. Kaikomagatake adds the rocky ridge (direct route) beyond Roppo-ishi and raises the difficulty.

The Futagoyama and Sensui-toge trails: the Futagoyama route is a long climb from forest into creeping pine; the Sensui-toge route crosses the large boulders of Sensui-toge. Watch for loose rock and falls.

The rocky ridge beyond Komatsumine: from Roppo-ishi toward Mt. Kaikomagatake the direct route is a steep granite face — beware of falls and rockfall. If unsure, take the path skirting Mt. Marishiten.

Weather on the ridge: above Komatsumine it is near the tree line, exposed to lightning, strong wind and sudden cloud. Carry a map and compass (GPS), and turn back early if a storm threatens.

Access constraints: the South Alps forest-road bus runs seasonally from early June to early November; outside this there is no public transport to Kitazawa-toge. Plan around the first and last bus times.

Season and gear: the season is early June to early November, while the forest-road bus runs and the huts are open (midsummer to the autumn colours is most comfortable). Carry rain gear, warm layers, a hat, gloves, a headlamp and plenty of water and food, and always file a climbing plan.

In an emergency: call 110 (police) or 119 (fire and rescue).
– Ina Police Station 0265-72-0110 / Nagano Prefectural Police mountain rescue unit

Photo by Σ64 / Wikimedia Commons, CC BY 3.0