Jakkun said:
My genjutsu idea would work too. Tsunade could have put a seal on him to make him look like Arashi or something.
One, Tsunade's perma-genjutsu is tied in to her Genesis Rebirth seal, which is why it doesn't drop even when she's injured. Unless she put that same seal on Naruto, I can't see a way to make it permanent.
Second, and much more relevant: Tsunade was NOWHERE NEAR KONOHA when Kyuubi attacked. Jiraiya mentions he hadn't seen her since several years before the Kyuubi attack, if you recall. And she's the only one who knows how to do that particular genjutsu, apparently.
Again, KISS. Making up an excuse for Tsunade to be in Konoha for the occasion would drag in the not-irrelevant question of why the Third Hokage didn't order her into taking the Hokage mantle herself. He'd have the authority to do so. And she can't get anywhere near the kid without his permission anyway.
It'd make things complicated, and complicated is bad.