Board Thread:Naruto Discussions/@comment-3279282-20140413164418/@comment-28861328-20140414021756

Kakashi states that all shinobi have the capability to learn additional natures. They only have one affinity, but, as demonstrated by Hiruzen, it is not a stretch for a particularly talented individual to mold and make use of other chakra natures. Kakashi even said that a typical jonin can produce three chakra natures and we know Naruto, while Genin in rank, is WAY more skilled than an average jonin. A bumbling idiot, yes, but no one can deny his talent.