There are some sites that sell K-pop physical albums (Amazon is a rip off, check the asian sites).
My GOD! Bar Bar Bar is so annoying now!
It was great the first three times I heard it on the radio, but now it's the Gangnam Style of 2013! I can't stop hearing it!
B.A.P's Japanese debut? I thought there were supposed to be subtitles because the first rapper was rapping in Korean, then the second rapper rapped in Korean again. The singers were singing in Japanese, though, so I don't know if this qualifies fully for a Japanese song.