Originally Posted by shinta|hikari
well we'll never know exactly how naruto got the 3rd and 4th tails. he got the 1st and 2nd in battle in confrontation w/ ppl he felt close to. he gets consumed by such chakra from the extent of emotion he feels in that moment.i'm not sure what kinda of anger unmanagement training jiraiya would have shown naruto in their 2 1/2 yrs away from everyone close to them for that much more chakra to consume him and get to the 3rd and 4th tails.
and yes i do realize it is not fact and my assumption that kakashi meant only naruto out of his teammates could do this special training. but it makes the most sense because the other 2 teammates make up the team, and Kakashi is training only this team.