I will go to Tokyo tomorrow and try to look for AT800 OF & DF. Is anyone know where & which shop that I can get those racket?

You can try find it in Windsor. But at the moment its out of stock.

Where is Windsor in Tokyo?

Refer to this thread

http://www.badmintonforum.com/vb/showthread.php?t=8182

http://www.badmintonforum.com/vb/showthread.php?t=8182

Thanks to the above old thread, I was able to locate the shop with some difficulties (the station is so big!) and bought myself a YY racket and a pair of shoes.