I know many of you like the canon characters of Naruto and Naruto Shippuden, and you would like to RP as them, I enjoy RP'ing them at times myself but they can also interfere with custom characters that others make when they can't for example make a kage or Akatsuki because of the canon spots filled.
I know your already shaking your head and ready to type keep it canon but just think about it.
When its customs only there are almost no limitations aside from the rules for you to worry about, and you could even use your favorite Canon characters picture and morph them into the character of your dreams or something. Not only that but you don't have to worry about the history of current Arcs in Naruto, No Leaf Village destruction or Bijuu being captured.
Theres just No true downside to making this a Custom Only RPG.