Im in japan to learn japanese, and when im not sitting teaching people english, or pretending to be german, i do spend alot of time studying it. I know im getting alot better at it, but as it always is with languages, i dont actual feel that i am.
Random (slightly) annoying things about japanese.
Vowel length. The difference actually matters between saying "o" and "oo"! When i was in tokyo there were two train stations, oyama and ooyama, which was somewhat confusing. Now the reason this is not just annoying is that oyama means small mountain, and ooyama means the exact opposite, big mountain. I think somehow that could be simpler...
Intonation. Its not as bad as in chinese, but sadly it too, matters in japanese. Depending on it, "kaeru" means either "return", "can buy" or "frog".
And then there are all the loan words from english. I acutally find these quite funny, I was at a restaurant last week when the girl behind me ordered:
chizuu omreisu esu seizu
Looks reasonably japanese right? well its based completely on english words:
cheese ommlette-rice s-size
Oh and just in case your feeling hungry there is also emu and eru sizes:)