u dont haveto be anyone ( i dunno why the name is slipping my mind but) the frog says u jus need massive chakra reserves to balance the nature energy and if u dont have it the nature energy will jus take u right over and other then naruto and jirya the only other one in the series that ive seen to have enough chakra to cotrol nature energy is kisame hoshigake (shark man) but one thing ive always wondered is who has more chakra naruto or kisame
edit: naruto only mastered it on the level that he did cuz he has a higher level of chakra then jirya and if kisame hasmore chakra then naruto wich i dont think he does but if he did then kisame could master it even more then naruto ....in theroy
It isn't the chakra levels that bring mastery of Sage mode. Obviously some people skipped over the parts where they explained that you had to be perfectly one with nature and your surroundings. High chakra levels are only needed so that you aren't overwhelmed by nature energy and turned into stone.
Naruto must have found the perfect balance between nature energy and his own chakra.
EDIT: to the naysayers, I am not saying for sure Minato had Sage mode, but it wouldn't be a huge leap to say that he had it. He had all of the requirements needed to master it, and had ample time. If Naruto could master it in a week I'm sure Minato would have learned in the 10+ years he had with Jiraiya.
The only argument against it is that it hasn't been shown in the manga. While this can sometimes be ok, this is also an idiotic argument. People right now are speculating about powers Tsunade might have, how is this any different? We have seen Minato in two real fights, both ambushes, and in neither one did he have any time to do anything other than react.
It's not like I am saying he had the rinnegan or some crazy stuff, this is a perfectly valid conclusion based off of evidence in the manga. Dispute it if you will, but you people are making assumptions same as I am, you can't deny that.