Pop'n Music is a Japanese game therefore it is to be played on a Japanese PS2... unless, like me, you've got a modded PS2.
My PS2 has a top reader and I also own Swap Magic discs. I got all of these things from a very nifty store called Game Play. I'm unsure if they have a website or not, but it's a fabulous store. Try looking it up. They sell top readers, Swap Magic discs, everything.
Hell, I even got Pop'n Music 13 and a Pop'n Music controller there.
Hope I helped at least a little bit.
__________________  Just sexin' it up. >3 | 
