This is my theory. Negi is Nagi.
This is going to go in depth on why I think Negi is Nagi. First of all the power level for Negi is probably the most ridiculously thing I have ever herd. People always say how much potential he has. So meaning that not really a kid has a power, but the power of an adult who knows a lot. A good point to prove is who is Negi's mother? Some how there is no information on who Negi's mother is. There is no possible way if you take the Aging pills you can look exactly like your father (This was irrelevant). Nagi said that Negi should stop trying to be like him so that points to "Just be your self since, I am you" So Basically Negi is basically achieving something that Nagi really wasn't. (Still cloudy of this meaning. Maybe no meaning at all.)
When you look at this
http://i36.photobucket.com/albums/e2...sumiyaMana.jpg
^This is a Pactio from another mage
http://diesgaudii.genvid.com/latin/l...evangeline.jpg
^This is Negi's contract with Evangeline.
http://i36.photobucket.com/albums/e2...lbireoImma.jpg
^How similar do they look to you? This is Nagi's with Albireo Imma.
This is what I am thinking. Some time back then Nagi and his gang were in a butt raping pinch. Leading to the death of takamichi's teacher and splitting up the group. Now Albireo Imma is trapped correct? And now comes out at festivals. So Nagi; seeing how he likes to be a trickster. (Refer to Volume 3 of Negima when Negi peeps in to Evangeline's dream. The garlic and leek trap he had made in the beach.) He made choice to wipe his memory and take the form of a child (So he could trick the people who intended to kill him). The only flaw to this is where the hell is the story to the gap between when Nagi turned in to Negi (Time Wise)? And another reason to this is Asuna is a princeces, so that would mean that she would always get targeted correct? Referring to the butt raping pinch that Nagi and His gang were in. (That caused every one to split up, and the death of takamichi's teacher.) With Takamichi watching over her. (NOT a coincidence) Untill Negi came Takamichi was not her teacher anymore. (Not knowing it would be Nagi, also not a coincidence.) So that would mean either Nagi got hurt REALLY bad, and took disguise. Or he is in disguise, so when a great danger comes towards Asuna's way Negi a.k.a Nagi would save her.
Some how I think Fate is also in the same situation with Negi.
The main flaw of this theory
-The Snowy Night 6 years ago.
-When Negi graduated from his magic academy.
-Negi being born.
-The staff Negi got from Nagi.
And the funny thing is we really dont know much about Nagi's Birth do we? So for all we can know he could be Japanese.

