I had to look it up as I had no idea what you were talking about....LOL
K-pop is an abbreviation for Korean pop music (also referred to as GaYo or KaYo music), specifically from South Korea.
J-pop, an abbreviation for Japanese pop, is a loosely-defined musical genre that entered the musical mainstream of Japan in the 1990s.
I actually listened to some Japanese music when we went there for a holiday last year, and since I have never listened to Korean music, will go with J-Pop.