How to embarrass yourself when entering a traditional Japanese hot-spring pool: about-turn immediately and head for the exit, your tail between your legs, at the first sight of a naked body.
Following proper etiquette is crucial in Japan and failing to do so is offensive as well as embarrassing.
But instead of calmly walking into the changing room without any hint of discomfort, I could only manage a startled face and a change of direction after opening the doors to two naked bodies: one towelling himself off, the other holding his frank in his hand and walking to and fro.
This wasn't exactly the ideal introduction to Japanese onsen - the mineral-rich geothermal hot pools, much like those in Hanmer or Rotorua, that dot the country.
For centuries, the people of Japan, which lies over active volcanic terrain, have enjoyed the natural benefits of the hot springs, which are said to be good for all kinds of ailments.
It's no wonder the Japanese take to them frequently and with vigour. And without clothes.
Which is the real issue; many New Zealand blokes find it hard enough to stand next to a bloke at a urinal, let alone bathe in all their naked glory in public pools.
The Japanese, having enjoyed onsen since they were young, have no such qualms.
After my first failed onsen attempt, I retreated to the small museum in the depths of the Fujiya Hotel in Hakone, Japan, and quietly remained until a few bathers had left.
Then, with my heart in my mouth, I re-entered the changing room to find ideal conditions: it was empty, though the little gathering of shoes on the welcome mat hinted at a spa full of naked men.
Sometimes bathers use the towel to cover the more sensitive areas - perhaps the gentleman with his hand full had mistaken his palm for the towel - but a quick survey of the room revealed everyone was just hanging out.
I walked in coolly, completely starkers, and marched up to the washing area, head down and eyes never moving from a spot about one metre in front of me.
The Fujiya spa is not exactly a picture of tranquillity; small, indoors, shallow and decorated sparsely by a marble statue of a naked baby boy in one corner, it's hardly the glorious pool nestled into some snow-covered alpine setting I had imagined - but still an authentic cultural experience.
Two elderly men sat in the spa, their legs stretched out before them. Three of the four wash stations were occupied by lathered-up bodies; the onsen is for soaking, not washing (indeed, there have been claims of xenophobia at some pools that forbid non-Japanese, but this has been defended as preventing foreigners from leaping into the spa without washing first).
Each station has a tap and shower head, enough shampoo for a small school, a bowl and a short, wooden stool to sit on.
I sat, soaped up and turned on the tap. So far so good. Now the shower head. The shower head. How do I turn on the shower head?
Great, I thought. I can't just sit here looking foolish, trying to squeeze myself under the tap. Nor was asking my neighbour for help an appealing option.
Then I realised: pull the lever up. The shower head sprang to life, and I washed. Quickly.
The actual spa - about 2m by 2m - is barely big enough for four people. I eased in and parked myself, legs crossed and knees up, in front of one gentleman and to the left of the other.
The guy behind me had his towel on his head - the towels never go in the pool - so I did the same, just as I became acutely aware of a procession of small waves lapping against me.
The man next to me was perched on one knee, steadily rocking up and down, as if practising for the aqua-bobbing world championships.
Was this proper etiquette?
And he just kept on undulating. Not even an alarmed look from me was enough to make him stop or even pause.
The awkward-meter was at its threshold when, after a few excruciating minutes, Bobby stepped out. As I took his spot, my back against the wall, I noticed I had the spa to myself.
Finally, time to relax. Spread the legs. Close the eyes.
The colourless, odourless water trickles into the pool at a steamy 42C, though it's actually closer to 60C when it enters the hotel pipes. The pool fills continuously, and the water overflows down a gentle slope to the drain.
The water was soothing, calming, natural. Healing? I'm not so sure, but it was pleasant to soak without the smell of chlorine burning the nostrils.
A younger man then appeared poolside, dropped his towel next to the spa and eased in.
He lasted the length of a pop song, re-washed and left. The next guy entered, came straight up to the spa and splashed a few handfuls of water on himself before heading for a wash. He too lasted but a few moments in the spa before getting out and leaving.
Just what is the proper routine?
Feeling thoroughly healed and infinitely prettier - not to mention wrinklier - I eventually arose and re-perched myself on a stool for a final wash.
I was much more relaxed: the shower came on immediately, and I even washed the stool.
The changing room was again - bless it - empty, and I took my time drying and getting changed.
The goodies on the bench provided for all sorts of grooming needs: a hairbrush, hair tonic, hair liquid - as opposed to tonic - and even aftershave.
I considered it my duty to partake of all of them. Anything less just wouldn't be polite.
Getting there: Air New Zealand flies to Tokyo.
Further information: See nto.go.jp.
Derek Cheng travelled to Japan courtesy of Air New Zealand and was a guest at the Fujiya Hotel, Hakone.