Well haven't you changed... Kyoya Hibari

Harry Potter, The 'Boy-Who-Lived' is not as, well, how do you put this, ignorant and stupid as he seems, hell, he's actually pretty smart and a bit more of a slytherin than he likes to admit. So when during the Battle of the 'death chamber' he get's hit with an unknown spell that 'shoots' him back in time and de-ages him, well he has to escape somewhere, because there can't be two Harry Potters now can there, especially when the other Harry is 2, and he has been de-aged to 4. So he decides to make a name for himself (other than the one he already has) and learn all he can. But before that he has to create a new identity for himself and get a new home. And where's the perfect place for that, well Japan of course. "You know what, my name will now be Kyoya, Kyoya Hibari! Or as the Japanese say it, Hibari Kyoya. Now just to get help from the Goblins, yeah, this is going to be tough!"