Man I was just wondering why kakashi could not recognise tobi by his voice???
I mean obito and kakashi were so close comrades, then why?
Same is the case whit obito's teacher minato. Even he could not recognise tobi in the past.
And what is the difference between kakashi's sharingan and obito's sharngan, I mean they both look different.
Yeah, those are some big questions. Why didn't Minato recognize the voice at all? Why didn't he recognize any of the other visible features (hands, ears, etc)? Maybe he just believed that Obito was dead so strongly, that he never made the connection. Of course, he also believed Madara was dead, and believed the masked man to be Madara so we're back to the beginning again.
It was only a few years between when Obito apparently died and when Tobi attacked the village. That's not really long enough for his voice to completely change tone or timbre. Minato should have recognized something was similar.
Also there are some things that you might expect a ninja as talented as Minato might recognize: fighting style, footwork, movements, etc. These are things that wouldn't change too much just from normal growth. We could say that Obito completely readapted his entire fighting style to use Kamui more completely, but that's a stretch. Remember, it had only been a few years, that's not a lot of time to make so many complete changes.
