Try to make it sort'a like SAO(Free roaming,hidden objects) Also(This may make it take longer but...) See if you can make it so that like when Kakashi Hatake says something you have like 3-4 different thing to say back.Also you should add a tailed beast system and a jinchuriki system where the kage can put a tailed beast in someone(every time a new kage is selected the old jinchuriki loses his tailed beast and a different person can have it(if the kage wants to).)But of course the village needs to encounter a tailed beast.Also add the chunin exams and different villages host it every year and have 1 every 9 weeks,4 in total.Also make it so your race is random otherwise everyone whould go for uchiha or uzimaki.Also make it so everyone will be in groups of three and when battling add [The Rising Fighting Spirit song].Also make like a better money system than the other MMO's (In General) like different jobs like doctor,Alchemist, Exc.(I watch a lot of naruto ).Thats all i can think of for now i send you guys more when i think of them,Love Naruto, Can't wait for the game see ya.