Japan's third-highest summit
Aino-dake's height has a small story of its own. The summit carries a third-order triangulation point, named Ai-no-dake, whose elevation the Geospatial Information Authority of Japan revised on 1 April 2014 from 3,189.13 m to 3,189.50 m. Rounded, that is 3,190 m, the same figure as Oku-Hotaka-dake, so since 2014 the two mountains share third place in Japan behind Mount Fuji (3,776 m) and Kita-dake (3,193 m). Among the top five, Aino-dake is the only one ranked by a triangulation point; Oku-Hotaka's figure comes from a spot height.
The mountain is massive rather than sharp. Seen from Kita-dake, from Nōtori-dake or from the Noro River valley, it is a wide, heavy dome, and its summit is a broad field of rock debris. Linear hollows near the top are thought to be the scars of large landslides, and the width of the summit has led geologists to suggest that before those collapses Aino-dake was several tens of metres higher. If so, at the height of the last glacial period, before Mount Fuji grew to its present size, it may have been the highest mountain in Japan.
East of the summit lies the Hosozawa cirque, a glacial bowl where snow lingers into early summer and where, in mid-July, the floor is covered with the yellow flowers of Trollius (shinano-kinbai). A second cirque faces north-east. The summit is a watershed: the south-western side drains into the Ōi River in Shizuoka, the eastern side into the Arakawa and the Noro River, which become the Hayakawa and join the Fuji River.
Where it is and how to get there
Aino-dake rises in the northern part of the Akaishi Mountains (Southern Alps), inside Minami Alps National Park (designated in 1964). The summit is shared by the city of Minami-Alps and the town of Hayakawa in Yamanashi and by the Aoi ward of Shizuoka city; the land to the south is the northernmost tip of Shizuoka Prefecture. Kita-dake is 3.3 km to the north, Nōtori-dake 2.9 km to the south, and Mount Fuji 55 km to the south-east.
There are two trailheads, both reached by seasonal buses from the Yamanashi side. Private cars are banned on the access roads during the climbing season, and outside it the roads are closed to all vehicles. In 2026 the restriction ran from 26 June to 3 November, with traffic allowed from 5:30 to 18:00.
- Hirogawara, on the Noro River below Kita-dake, is the start of the traverse. Yamanashi Kōtsū buses run from Kōfu Station in about 1 h 55 min for ¥2,400 (2026); drivers park at the municipal Ashiyasu car park and take the bus (¥1,450) or a shared taxi (¥1,400) for the last hour.
- Narada, a hot-spring village in Hayakawa, is where the traverse ends. A town bus links it with Minobu Station on the JR Minobu Line in 1 h 30 min (¥1,000), and a bus runs between Narada and Hirogawara in about 45 minutes (¥1,300). Drivers can park at Narada and ride up to Hirogawara to start.
On top of each fare a voluntary contribution of ¥300 per person per ride is collected to pay for the car restriction. The bus between Hirogawara and Kitazawa Pass, the old link to the Senjō-ga-take side, was suspended again in 2026 because of road damage from the 2019 typhoon.
Routes and huts
The Shirane Sanzan traverse (Hirogawara to Narada). This is the classic way up Aino-dake and one of the highest ridge walks in Japan, crossing three summits over 3,000 m. The reference times below are from the Minami-Alps city mountain museum's guide; real times vary.
- Hirogawara to Shirane Oike hut (about 2,200 m): 3 h through steep forest.
- Shirane Oike to the Kotarō ridge by the Kusasuberi slope: 2 h 30 min; then 30 min to Kitadake Kata-no-koya (3,000 m) and 50 min to the summit of Kita-dake (3,193 m).
- Kita-dake to Kitadake Sansō (2,900 m), on the saddle below Naka-Shirane: 50 min down a rocky ridge with chains and railings.
- Kitadake Sansō over Naka-Shirane (3,055 m) to Aino-dake: 1 h 40 min (1 h 20 min the other way).
- Aino-dake to Nōtori hut (2,800 m): 1 h down (1 h 30 min up), across a double ridge with hollows where the path is easy to lose.
- Nōtori hut to Nishi-Nōtori-dake (3,051 m): 50 min; on to Nōtori-dake (3,026 m): 40 min; then 30 min to the Daimonzawa descent point, marked by a steel tower with a bell.
- Descent point to Daimonzawa hut (about 1,765 m): 3 h of steep, rough path; then 3 h down the valley, over suspension bridges, to the Narada No. 1 power station, and about 40 min along the road to the bus.
The usual plan is three days: night one at Kata-no-koya or Kitadake Sansō, night two at Nōtori hut or Daimonzawa hut, and the walk-out on day three. Fit parties do it in two by sleeping at Kitadake Sansō and descending all the way to Narada. The traverse is also walked in reverse, but the climb of about 1,000 m from Daimonzawa hut to the ridge, through forest with no view, is long and hard. The Ōkanbasawa valley route from Hirogawara to Kita-dake is closed: the riverbed keeps shifting after typhoons and temporary bridges cannot be kept in place, so use the Shirane Oike trail.
Out and back from Kitadake Sansō. Hikers who want only the two highest peaks can leave their pack at Kitadake Sansō and walk to Aino-dake and back in about 3 hours, then return to Hirogawara the same way.
Onward along the main ridge. At the summit the trail splits. Left (south-east) goes to Nōtori-dake; right (west) goes to Mitsumine-dake (2,999 m), where Yamanashi, Nagano and Shizuoka meet, and down the Senshio ridge to Kumanodaira hut (about 2 h from Aino-dake) and on to Shiomi-dake (3,052 m), roughly 5 h from Aino-dake. This is the start of the long north–south traverse of the Southern Alps.
From the west via Ryōmata. The only route that climbs straight to Aino-dake starts at Ryōmata hut on the upper Noro River: 1 h to the Norogawa-goe saddle, 3 h of steep forest to Mitsumine-dake, and 1 h over sand to the summit. Reaching Ryōmata itself is a long walk up the forest road from Hirogawara.
Huts. Kitadake Sansō, Shirane Oike hut and Hirogawara Sansō are run by Minami-Alps city and must be booked in advance through the city's reservation system; bookings for 2026 opened on 1 April. Kitadake Sansō, with space for about 150 people and a campsite, also hosts the only summer clinic in the Southern Alps for part of the season. Nōtori hut, sheltered behind a stone wall on the saddle, holds about 120 and has a campsite; Hayakawa town directs bookings to the Daimonzawa hut operator. Hut seasons are short: in 2026 Kata-no-koya was open from 26 June to 25 October, and Nōtori hut and Daimonzawa hut open roughly from July to late September or mid-October. Prices change each year, so ask the huts directly.
Rules and climbing plans
There is no entry fee for the mountain itself; the costs are buses, huts and the ¥300 contribution per ride. Under Yamanashi Prefecture's mountain safety ordinance, in force since 20 October 2017, climbers are asked to file a climbing plan (tozan todoke). The Yamanashi police accept plans through the Compass online system alone, by e-mail or by fax, and there are boxes at the Hirogawara information centre and Hirogawara Sansō; huts also take them. Camping is allowed only at designated hut campsites, and the national park's usual rules apply: no picking plants, no fires, carry your rubbish out.
When to go and weather
The practical season is July to early October, when the huts are open and the buses run. In early July snow can still lie in the gullies and cirques, and the alpine flowers peak in July and early August. Summer brings typhoons and afternoon thunderstorms; the exposed ridge offers no shelter, and two climbers were killed by lightning on the rocky ridge just south of Kita-dake's summit in July 1939. Autumn weather varies from year to year: in 2026 September was rainy and October mostly clear. By late October the ridge can be icy. After 3 November the access roads close, the huts shut and the mountain becomes a serious winter objective.
In winter, climbers approach on foot along the closed roads and climb the Ikeyama-tsurio ridge to Kita-dake, or Aino-dake's own eastern spurs, the Onashi ridge and the Kōbō-goya ridge. Some huts leave a room open as an emergency shelter outside the season. The Hosozawa cirque is used for ski descents in spring.
Water
There is no water on Aino-dake's summit or on the ridge between Kitadake Sansō and Nōtori hut, so carry at least 1.5–2 litres for that stretch. Nōtori hut has its own water source, and Shirane Oike hut is fed by a stream. At Kitadake Kata-no-koya the spring is 15 minutes below the hut, and the hut also sells water (¥200 per litre in 2026). The first trickle of the Ōi River appears at about 2,850 m beside the traverse path from Nōtori hut to Kumanodaira, but it should not be relied on late in the season. Treat stream water before drinking, and buy drinks at the huts on hot days.
Mobile coverage and emergencies
Coverage on the Shirane Sanzan is patchy: on the open ridge a signal is often available, but expect it to drop out in deep valleys and forest, such as the Daimonzawa descent. Carry a power bank and download offline maps. In a mountain accident call 110 (police, who run mountain rescue in Yamanashi); for fire and ambulance call 119. Rescue costs can be high, so mountain insurance is strongly advised.
Dangers and safety
The main danger on Aino-dake is getting lost. The summit is wide and flat, and the descent towards Nōtori hut crosses a double ridge with hollows where the view disappears in cloud; follow the red paint marks carefully. The Daimonzawa descent point is another place where parties have missed the way down in fog. Other hazards are wind and cold on the 3,000 m ridge, lightning, slips on loose rock (the section between Nishi-Nōtori and Nōtori sees many falls) and exhaustion on the long descent to Narada.
The history of the ridge is a list of warnings. In July 1952 two climbers died of exhaustion and cold in a storm near the Hachihonba junction below Kita-dake, and two more died there in October 1962. In November 1962 a party of five lost their way descending towards Nōtori hut in a blizzard, and four died. The journalist Honda Katsuichi later analysed the accident and found that the four who died wore cotton underwear, while the survivor wore wool. Yamanashi recorded 192 mountain accidents in 2025 (40 more than in 2024), and the Southern Alps accounted for 71 of them, the most of any range in the prefecture.
Ptarmigan are often seen around Nōtori hut and the Mikuni-daira area. Yamanashi police advise carrying a bear bell in the forests.
History and name
Aino-dake first appears in the Kai Kokushi, the gazetteer of Kai province, in 1814, but not under its present name: the gazetteer called it Nōtori-dake and gave today's Nōtori-dake a different name. The dispute was settled by the snow: in spring a bird-shaped snow patch, the "farmer's bird", appears on the eastern face of today's Nōtori-dake and once told farmers it was time to plant rice, so that peak kept the name, and the middle summit became Aino-dake, "the peak in between". Later it turned out that Aino-dake has a "bird" too: a snow figure like a black dove flapping its wings appears in the Hosozawa cirque.
The British missionary Walter Weston climbed Aino-dake in 1904, together with Kita-dake, Hōō-zan and Senjō-ga-take. In July 1908 the writer Kojima Usui and his companions traversed the Shirane Sanzan from the south. The first winter ascent was made on 22 March 1925 by Nishibori Eizaburō and three others from the Third Higher School in Kyoto; Nishibori later led the first Japanese wintering party in Antarctica. Keiō University climbers made the first midwinter ascent on 4 January 1928.
On New Year's Eve 1955 four members of the Yamanashi University alpine club pitched their tent on the summit at the end of an 11-hour day from Ryōmata over Kita-dake. They were seven days into the first midwinter traverse of the entire Southern Alps, which had started at Kai-Koma-ga-take on 24 December; they reached Tekari-dake, at the far southern end of the range, on 18 January, 26 days after setting out.
Interesting facts
- The Ōi River, about 160 km long, flows entirely through Shizuoka Prefecture, and its source is marked by a wooden post on Aino-dake's southern slope.
- Mikuni-daira, the flat below Mitsumine-dake, is named after the three old provinces of Kai, Shinano and Suruga that meet there.
- Aino-dake is also one of the 100 Famous Mountains of Yamanashi, chosen in 1997.
FAQ
How high is Mount Aino? 3,190 m (3,189.50 m at the triangulation point since the 2014 revision). It is tied with Oku-Hotaka-dake as the third-highest mountain in Japan.
How long does it take to climb Aino-dake? Usually two or three days as part of the Shirane Sanzan traverse from Hirogawara to Narada. From Kitadake Sansō, the round trip to the summit takes about 3 hours.
How difficult is it? It is a hike on marked trails with no technical climbing, but it is long and high: steep forest climbs, a rocky ridge with chains near Kita-dake, and hours above 2,800 m. Good fitness and experience of multi-day mountain walks are needed.
How do I get there from Tokyo? Take the train to Kōfu, then the seasonal Yamanashi Kōtsū bus to Hirogawara (about 1 h 55 min, ¥2,400 in 2026). The traverse ends at Narada, with buses to Minobu Station.
Do I need a permit? No permit or entry fee. Book the huts in advance and file a climbing plan with the Yamanashi police, for example through Compass.
Is there water on the way? Not on the summit or the ridge itself. Get water at Nōtori hut, Shirane Oike hut or Kata-no-koya, and carry 1.5–2 litres between huts.
Is there mobile phone coverage? Often on the open ridge, rarely in the valleys. For a mountain accident call 110; for an ambulance call 119.
When is the best time to climb? July to early October, when the huts are open and the buses run (in 2026, 26 June to 3 November). Midsummer brings flowers and thunderstorms; by late October the ridge can be icy.