We progress gradually higher, through Station Six, with the route becoming progressively steeper and the vegetation disappearing entirely above New Seven. Instead, the vista is almost lunar with each step kicking up a miniature tornado of volcanic dust.

By the time we reach the Miharashi-kan Hut, at 3,250 metres, the light is fading and the wind is whipping across the barren mountainside. Inside, however, is warm and cosy - although a visit to the primitive outdoor toilet is a test of endurance.

Traditionally, Japanese climbers aim to reach the peak of Mount Fuji in time to see the sun rise over the Pacific. To be punctual, many people climb through the night, although a better option is probably to book a night at one of the huts. Mr Hatakehori has thoughtfully brought a bottle of sake with him, for medicinal purposes.

With the morning call set for 1:30am, in order to complete the climb before sunrise at 4:45am, we are in our communal bunks before 9pm. The two-tiered wooden bunks use a heavy futon as a mattress and guests share the thick eiderdowns, sleeping shoulder to shoulder. Cosy to some; claustrophobic to others.

The wind has not abated during the couple of hours of sleep that we were able to grab and emerging from the warmth of the hut is a shock to the system, even with every layer of clothing on. And there are not many places in Japan where one needs so much protection in August.

The climb recommences with the way lit by wavering torches, which shrink the walkers' world to a small pool of light surrounded by inky darkness punctuated by other lamps. The occasional shooting star hurtles across the heavens, breaking the monotony of what has become something of a slog. We pass the remaining huts that line the route to the top, overtaking and being overtaken by other groups of walkers in turn.

The congestion worsens the closer to the top that we come - some 2,000 people climb the volcano every day during the peak months of July and August - and our pace inevitably slows.

Around 100 tantalising meters below the stone "torii" archway that marks the top of the mountain, it is clear that the sun is going to put in its appearance before we can reach our goal. Like dozens of others, we instead select a spot alongside the path and watch as the sky changes through deep oranges to pale yellow and the golden orb climbs through the cloud cover. It is an impressive start to another day in the land of the rising sun.

The peak, when it comes, is something of an anticlimax. It is thronged with hikers in brightly coloured outfits rubbing aching legs or taking photos alongside the stone monument. I drink three cans of hot, sweet coffee in an attempt to rid myself of the headache that I have had for the last couple of hours, apparently brought on by the altitude. Maybe the people buying the gas canisters were wise after all.

A complete circumnavigation of the crater takes an hour or so, but I prefer to conserve my energy and satisfy my curiosity for seeing what the inside of a volcano looks like. Steep-sided and with lines of different coloured rocks in layers, it is deceptively peaceful. The last time Mount Fuji erupted, the streets of Tokyo - 50 miles to the west - were coated in ash.

Rested, we begin our descent of Japan's holy mountain. Unsurprisingly, it is at a far faster pace than the ascent. Clouds of dust kicked up by our boots float over the mountainside and the layers of clothing come off one by one. And as the souvenir shops of the fifth station again come into view around the final bend, Mr Hatakehori still has not broken into a stride. It's still shuffle, shuffle, shuffle.

For more information about climbing Mount Fuji, see the Japan National Tourist Organisation website

Times recommends

• Britain's top 10 New Year's Day brunches
• Mozambique's lost islands
• The best things to see and do in 2010