Ryu and kors K made their debut with "beatmania IIDX 4th style" in 2000 who now celebrate their 20th anniversary releasing a two disc CD as new unit "The 4th". Disc 1 contains 13 titles including popular tracks from BEMANI series in long versions as well as "starmine (kors k Remix)" and "Clione (Ryu Remix)", perfect for the 20th anniversary release. Disc 2 includes 7 titles.