[pokori]

I think Chinese grammer is easier than Japanese.
But Japanese pronounciation is easier than Chinese. I think Chinese pronounciation has more variety, and some sound is really hard to pronounce for me (Japanese). Plus, the 4 tones....
I think Chinese polite form is not as nearly complicated as Japanese one, you can talk to teachers and friends in almost the same way, where in Japanese that won't be the case.
And in Chinese maybe there are more words you need to memorize newly because they translate foreign words like spoon, fork, ski, icecream, download, etc... but in Japanese you just need to know our accent for those words.
Well, I didn't learn Japanese as a foreign language, so it's hard for me to say which is more difficult to learn... but I learned Chinese for three years and found it pretty hard. (although I originally thought it's gonna be a piece of cake since I use Kanji as Japanse... of corse reading is easy for me, but still...)