when i lived in japan, i would regularly go to the hotsprings with friends, completely naked of course. most of the hotsprings are either men or women only, so this basically meant hanging out (literally) for much of the weekend with other guys; some friends, most complete strangers.
even for office year-end parties, it was common to go to the hotsprings. with a couple exceptions, i basically saw everyone in my office naked.
i can't imagine this situation in America.