The second game follows Ulala as she faces off against a new group of enemies called the Rhythm Rogues (踊り団, Odori-dan?), led by the mysterious Purge and his masked assistant Shadow. The Rhythm Rogues kidnap thousands of innocent people, including Space President Peace, and force them to dance.
Space Channel 5: Part 2 was released in Japan on February 14, 2002 both for the Dreamcast and PlayStation 2. The PlayStation 2 version was released in Europe (except for the UK) on February 12, 2003, and in North America as part of special edition package with the first game on November 18, 2003.
Source: Wikipedia, "Space Channel 5", available under the CC-BY-SA License.