As an aside, Hadakanbo Education is an odd word. The term is... Hadaka (naked), but "nbo" is gibberish as far as I can tell. I think it's a parody of another term, but can't figure it out.
It's not "nudist," although Chika's lecture early on is almost spot on to the talking points Japanese nudists use when describing Nudism to others. Maybe "Nakedian Education" or somesuch?