Aron is French (he has a background in Japanese on his mother's side of his family, so that's why he knows some Japanese).  He came to Tomoeda, Japan sometime in 3rd or 4th grade, and he did attend Tomoeda Elementary, but was never in Sakura's class.  Aron is in Sakura's 7th grade class.  Aron's name is (supposed to be) French, so his name is in katakana and has no specific meaning in Japanese.