One of life's little differences in Japan was that, every once in a while, you'd be standing at a urinal in an office building bathroom, and the next thing you know -- there's a little old lady in a uniform cleaning the bathroom around you.
The first time this happened to me, I was at Canon. I was standing there, absent-mindedly doing my thing, when all of a sudden, a woman walked in and began to clean the urinal next to me. I was so surprised, it nearly caused me to miss.
Over the years, I saw enough cleaning ladies in men's bathrooms, gym locker rooms, etc., that I got used to it. I came to realize that, unlike Americans, Japanese don't sexualize nudity unnecessarily. Nudity is sexual when people are having sex; at other times, it's just an absence of clothing. Men and women bathed naked together in public baths before prudish Victorian-era westerners arrived and told them to cut it out if they wanted to be considered "civilized" and not get colonized for their "own good." Even though there are only a few places -- mostly in rural outposts -- where men and women can still enjoy the public baths together, it's still very common for couples to bathe together in private baths at an onsen (without it being foreplay -- don't think of the heart-shaped bubble bath from old Love Boat episodes!), and Japanese parents often bathe with their children at home, at least until the children reach puberty. It's not considered sexual, it's considered essential for families to feel close to one another.
Nonsexualized nudity. It's so . . . civilized.