Wikipedia
Rokuko
"Rokkugo" is the first CD single by Super Junior-T, released on February 23, 2007. Over 45,997 copies were sold by the end of the year, marking it Korea's sixteenth best-selling record and #1 best-selling single of 2007. "Rokuko" has been one of Super Junior's most well-known songs.
Super Junior-T re-released this single in Japan on November 5, 2008, collaborating with the Japanese female comedy duo, Moeyan.