Sometimes going naked and soapy is the best way to meet locals in a foreign country. Perhaps nowhere is this more true than in Japan, and particularly Tokyo, where public baths remain popular, although most people now have bathrooms at home.
The Japanese see bathing as a great social leveller - yakuza bosses will rub shoulders with priests, for example - so public baths remain heavily subsidised by the government. It allows the baths to be located in some extremely expensive neighbourhoods.
Azabu-Juban Onsen (below) is a 10-minute stroll from the glitz (my five-star hotel) and grit (the strip clubs) of Roppongi.
The grey frosted windows conceal an explosion of outdated decor (the walls are brown, crusting laminate) and patrons (most of the bathers are old, pale and wrinkly).
The bath mistress is perched on a raised chair and oversees all activities in the male and female sections (apart from her vantage point, the two areas are separate). It costs only 400 yen (HK$27) to enter and a few dollars extra for some soap and a flannel.
There are lockers for your clothes, so once you have your kit off you go from the changing room into the bathing room where there are 20 or so taps raised a metre off the tiled floor. You sit in front of your tap on a plastic stool and scrub away. Most of the room is covered with mirrors so you cannot escape catching other people's eyes, or worse, their posteriors.
You must not leave an inch unscrubbed because afterwards you share a large, exceptionally hot, bath with about 10 others. I tried to ignore the fact that the bath water was brown and instead imagined that it was filled with ancient natural salts that would make me younger.