Well. I realized it when the 4th Hokage was shown on the statue and Naruto dad suddenly went MIA. then i thought. These mofos look IDENTICAL.. I kinda knew it before sauske went Rogue
This^xdAs soon as I saw the picture of the 4th when Hiruzen and Anko were talking about him.
I figured it out fast, cause they look alike and naruto looks up to him alot, i knew there had to be some connection
Same here me and my bother, and dad ( I know weird right) were watching Naruto and then my dad said:Very first I saw him. Lol it was soo obvious! xd