hi taskin ayu!
i think I can help you... i buy my J-pop in hong kong... let your friend check out HMV stores... the biggest ones are in tsim sha tsui and central and almost everyone in Hong Kong knows where the HMV stores are... it's easy to get there by MTR. HMV sells both overseas and japanese editions... but jst so you know, the cd+dvd japanese versions are limited in Hong kong. Get them early!
The hong kong records store in the ocean centre mall (again, everyone knows where this mall is... it's HUGE!) has j-pop, too.
I can even give you directions. jst send me a private message if you want to know more
