There several models in Japan, but the one closely resembles the US spec WRX is called NB with 250hp and 17 inch wheels.
The changes are:
The sterring wheel changed sides (duh..)
The Momo steering wheel(we have the little logo, they have the siver badge)
The stereo system (Kenwood vs. I don't know what)
The seats (they have semi-racing looking seats, we got the base model Impreza seats)
AVCS (Active Valve Control System)
A slightly alrger turbo running slightly higher boost
17 inch wheels
These are probably it. The STi has more goodies, but too many to list and too hurtful to mention
goto
www.subaru.co.jp