1) they're not free. The whole album (12 songs, 25 minutes) costs 1.200 Yen, that is ~13$/9€.
2) they're NOT DRM-free. Yeah, that sucks terribly. Now, please note you won't be able to share those songs with anyone. You can only read them on ONE computer. Yeah, that REALLY REALLY SUCKS *SSES.
3) they're WMA. Looks like the DRM restrictions didn't suck badly enough, yeah.
3) you need an international credit-card (like a VISA or a MasterCard) to buy the songs
4) it looks like you need to use Internet Explorer to buy the songs, and Microsoft Media Player to extract them on your computer (then, you can read the files on another Media Player that supports DRM, like Winamp for example)
5) you need to have some very basic knowledge of Japanese in order to create an account, and buy the songs. You don't need to be perfectly fluent, what you need to know, for example, is to be able to read katakanas. You can also use Google Translations to help you with kanjis.

http://www.megaupload.com/?d=B1VUYN3F

Please note that it took me almost two hours to write this tutorial. Yet, it's kinda messy, there are probably a few spelling mistakes (and such) left, but I hope it's clear enough!
Following the instructions written in that tutorial, I was able to buy the songs, but please note that it might now work with you, but there's really no reason it shouldn't work with you.