KEY POINTS:
I'm shivering in a toilet three-quarters of the way up Mt Fuji. My four climbing companions and I have organised ourselves into a toboggan-like sitting arrangement on the floor and only just fit into the small wooden structure.
This isn't as strange as it sounds - a toilet being on the side of a mountain in Japan, that is. After all, this is the country where you can buy disposable clothes from a vending machine.
The fact we're cuddling each other without embarrassment might seem weirder.
But when your face is so cold you can hardly feel it, your teeth are chattering like a chainsaw and your toes seem to be suffering from the early stages of frostbite, wrapping your arms around another man and wondering what it might look like if a stranger walked in just doesn't seem to matter. What matters is keeping warm.
Earlier that day, we had boarded a bullet train at Shin Osaka station north of Osaka City and caught a bus from Shin Fuji station. We were dropped off at Fujinomiya/Mishima 5th Station, which is about 2700m above sea level and one of the 10 stations the mountain is divided into.
Most climbers start from one of the fifth stations, which can be reached by road and approached from different sides of the 3776m mountain. It takes about four and a half hours to climb from one of these stations to the summit.
To kill time, so that our triumphant ascent would coincide with the 4.30am summer sunrise, we hung out in the station's cafeteria for a couple of hours until the surly proprietor tired of our mooching and shooed us away.
Off we went at 9.30pm into a light drizzle - novice climbers clad only in shorts and parkas. But surely adequately attired - Mt Fuji is frequently climbed by children and grandparents. In a few hours, our lack of respect for the mountain would come back to haunt us.
Very quickly, we divided into three groups: pacesetters, Englishmen Grant and Aaron, who leapt up the trail like demented gazelles, with me in the middle and Mike from Oregon and Carl from London lagging behind.
The higher we climbed, the darker, wetter and colder it became. Along the trail are a number of stations and huts offering food and accommodation (if you book ahead, as we would find out later).
At most of these we stopped, allowing Mike and Carl to catch up. Each time we stopped, though, we had to wait just a little bit longer for them to materialise.
There is a quiet you experience on top of a mountain, as you stare out into the black starry night, that defies description. It is so calm, not even your mind can interrupt the tranquillity.
But a voice can. A gruff and concerned American accent cut through the still air, ruining my moment.
"We ... need ... to ... have ... a ... meeting," said Mike, puffing up the path ahead of a wheezing Carl. "You guys need to slow down."
Having almost reached half way, Aaron and Grant were ready to get going again, but we decided to walk together - at a more leisurely pace.
The progress we were making, even with Mike and Carl holding us back, meant we'd be at the peak well before sunrise and, at that time of the day, we knew it was damn cold up there.
So, after trying our luck at staying for an hour or two in some of the huts on the way up - and being turned away because we had no booking - we end up huddled together in a toilet. And we don't have it all to ourselves.
As the feeling in my face starts to return, the door opens and a middle-aged Japanese woman gets the fright of her life. She runs off and seconds later returns with what must be the manager, who screams at us to get out.
We reluctantly disentangle ourselves and head out into the cold. But when she returns to the main building, we're quickly back in the loo, huddling up against the cold.
Before long, though, we're booted out again - drawn this time to the noise of machinery coming from a small building. In we go to find a generator pumping away, giving us the heat we crave.
I press my face against it and it feels wonderful. But just as I'm beginning to get used to it, we're uncovered and kicked out again. So onwards we go - trudging up the mountain and hitting the last station before the summit at 3am.
The first signs of altitude sickness kick in and, unable to walk in a straight line, I start to zig-zag up the path. But we eventually reach our goal ... and come face-to-face with a souvenir shop. Only in Japan.
It's getting lighter, but we still have an hour before the sun comes up. We head to a flat part of the mountain and wait, shivering.
Slowly night is replaced by day and, from way over on the horizon, a bright orange ball begins to push itself out of the clouds. It takes me a few moments to realise the globe is actually the sun.
As it gets nearer, light splays out all over the sky until it is a vivid blue.
The otherworldly landscape of the mountain we're standing on starts to take shape and it feels like we've landed on another planet. We're above the cloudline and they look so thick we feel as if we could walk across them. It's glorious.
I take a big gulp, and our party of idiots is gobsmacked at the beauty of it all. Happy to be warm. Lucky to be alive, some might say.
Aidan Rasmussen climbed Mt Fuji his own way and at his own expense.
