I listen to japanese music only.
For me, Japanese is such a melodic language. I have never heard another language, that sounded more awesome than Japanese. I'm now 23. I started to listen to J-Pop when I was 14.
The main problem in Western music for me is, that I understand the lyrics. I don't want this! If you love a song that you can't understand lyrically, you have extremely much space for your own fantasy. That's why I usually don't read english-translation of Ayu's songs. I don't want to know the lyrics! I want to decide, what the songs means to me, without having the actual lyrics in my mind. That's the biggest reason, I prefer Japanese for songs.
Beside that, I never really listened to commercial western music before I started to listen to J-Pop. I was busy playing Game Boy and N64 xD
I don't mind western music though. It may exist, but not for my personal music preferences
