I worked for AEON from 2001 to 2003. I did my interview in Vancouver, where they had one on one interviews, so if you are doing it anywhere else I won't be able to offer much advice because the process is not the same.
One word of advice I can give you is if they ask where you want to work, choose somewhere in Western Japan. The company is divided into AEON west and AEON east, and the management style is quite different between the two. I've heard nothing but bad things about AEON east, but I worked in the west where the head office was fairly helpful and not a hassle. If you want to live in Tokyo, then you'll be stuck with AEON East, but if you don't mind working elsewhere I suggest a place in west Japan.