This is the Japanese version of the first IIDX ever released. A lot of the sound effects are identical to Beatmania Complete Mix 1 and it has an extremely similar vibe to the older 5key games. There are only a few songs and the credits video shows people playing 5key on extremely old Beatmania cabinets in Japan. Unlike the international release, this one has a warning stating its for play only in Japan. It also includes internet ranking mode for high scores which seems absent on the international version. 4-key mode is available in single and double play styles, and the game must be put into battle mode like 5key in order to play both players simultaneously.