Japan is two-thirds mountains with an extensive hut network, and the huts work differently enough from European ones that it changes how you plan.
How the huts differ
More crowded. Futons laid out side by side, and at peak times sometimes shared between walkers. This is normal and is not a failure of the hut.
Fixed meal times, served to everyone at once, usually a set menu.
Lights out early, with a pre-dawn breakfast, because everyone is walking at first light.
Cash is frequently required.
Reservations increasingly required, which was not traditionally the case. Turning up unannounced is no longer reliable — check each hut's current policy.
The atmosphere is communal and more regimented than an Alpine hut, and the food is considerably better than the equivalent.
The Northern Alps
The best multi-day walking in the country.
Kamikōchi is the gateway — a valley closed to private cars, reached by shuttle from Hirayu or Sawando.
Kamikōchi to Hotaka — the classic traverse, climbing from the valley to the Hotaka range over two or three days.
The Daikiretto — the ridge continuing to Yari-ga-take, seriously exposed with chains and ladders, and not something to attempt casually or in poor weather.
Yari-ga-take itself, the spear-shaped peak, with a scramble to the summit.
Tateyama and the Kurobe Alpine Route, crossing the range by a chain of cable cars, buses and a trolley, with walking at the top.
Hokkaido
The Daisetsuzan traverse — Japan's most serious multi-day wilderness route, crossing the largest national park over several days with limited hut provision.
Brown bears, weather that turns quickly, and a requirement for self-sufficiency that Honshu routes do not impose.
A shorter season, roughly July to September.
Shiretoko, the UNESCO peninsula, with access restrictions at times because of bear activity.
The pilgrimage routes
The Kumano Kodo — ancient routes through cedar forest on the Kii peninsula, linking three grand shrines, and a UNESCO site alongside the Camino.
Sections walk in three to five days, with onsen towns at the ends of days and luggage transfer available. The best-organised multi-day route in Japan for independent walkers.
The 88-temple pilgrimage on Shikoku — six weeks on foot for the full circuit, and sections work as a week.
The Nakasendō, the old post road, with the Magome to Tsumago section as a half day through preserved villages.
Yakushima
An island of ancient cedar forest off Kyushu, some trees thousands of years old.
Jōmon Sugi as a long day walk along a disused logging railway, and multi-day traverses across the island.
It rains constantly — this is the wettest place in Japan and the reason the forest is what it is.
Practical
Season: July to October for the high mountains, with snow into July.
Autumn colour fills huts with domestic walkers — book well ahead.
Submit a climbing plan (tozan todoke) in the boxes at trailheads. Search and rescue works from these.
Bear bells are standard practice, and essential in Hokkaido.
Rural buses run infrequently — check the last departure before setting out.