File Sharing for Japanese music

I just re-installed Windows, and want to update some programs.
When it comes to sharing music i'm wondering which file-sharing programs are good right now, and what people are using..
i'm considering maybe a file sharing application like; Limewire, Kazaa, WinMX or eMule? (wondering if any of them are good right now)

Its hard to decide what to install because i usually search for really new or kinda rare Japanese music.
Any recommendations? ideas? links?
:music:
what i mean by "rare" are songs easily found in an updated Japanese Karaoke book, but harder to find when trying to download the mp3 from the internet.

Be very careful about posts like this. Filesharing music is illegal and music companies are starting to come down hard on people that do it on a regular basis. On that I will close this thread due to the subject