While I do not speak either Japanese nor Korean, I can recognize the differences between the two, and I've listened to this song enough in both languages to tell the difference. This is definitely the Japanese version, from Girls' Generations "1st Japan Album" that was released in Japan but is, as far as I can tell, NOT available via U.S. iTunes; there are instrumental versions available on some J-Pop compilation albums, but not this Japanese vocal track. Which is annoying and disppointing, since they're cutting out a potential US market in Anime otaku who love J-Pop/J-Rock but may not yet be into any K-Pop...like yours truly (though I do like PSY and Hyuna Kim).
