In the Space Year 1422, the interplanetary monetary system collapsed, causing all of the planets in the Fantasy Zone to become panic-stricken. An official inquiry made by the space guild reveals that someone is leading the Menon planet forces, using them to steal the foreign currencies of the other planets and construct a huge fortress in the Fantasy Zone with the stolen funds. To put an end to the Menon forces' ambitious plans, Opa-Opa promptly takes off for the Fantasy Zone.
