Quote Originally Posted by Shadow Skill
A lot of Japanese courses tend to teach Japanese with slang now... which I think pollutes the minds of those to try to learn the language. Best advice, find a 60 y.o teacher who's Japanese and get lessons. :P
That's a bad idea. Japanese is one of the most evolving languages, as they often adopt words from other languages, make expressions old-fashioned and obsolete, and shorten words and combine them into new terms.

If you learned the classical language from an outdated source, you would not be able to converse in the real world. Girls would call you kakko warui, and most Japanese under 40 would just not understand you. Also, the language in anime and other media would sound weird to you.

@animus: I doubt it. Were there any other characters with slang anatomical names?