hmm,practice are essential but it takes too long mate. How about shorten or lower the standard from the recent standard a bit?
Thanks to that practice i can remember difficult kanji over and over again.
Another is, why not after passing vocab and kanji test, u can reward badge(make a variety badge?) like kanji's ninja, or kanji's ghost or kanji's king etcs) so ppl can collect badges. :P and lock up more by doing more practice to attract members.Oops long.:) and i know this sound funny but can we have japanese song karaoke contest in here?