good advice by dr1ft.jp, i highly recommend Mobara, awsome track, the others are ok to get to, there is a station very close to tsukuba, if you are good with your directions, only 6km to track! Fuji again is easy got to, but buses only run at weekends to circuit i believe! Autopolis is out of the question man...Hey dr1ft.jp, il be back in Osaka next week, you never know, could hit you up for a beer if you buying haha