One of the world's most powerful super computers runs a recently built island resort in Tokyo Bay that holds a grand opening party attended by the City Hunter gang. However, only Miki and Kaori make it. During the event, General Gillium, a banished South American dictator, takes all guests hostage, including Miki and Kaori. The situation calls for Ryo and Umibozu to rescue the hostages and thwart Gillium's daughter's plans to use the supercomputer to launch a nuclear attack on the USA.