Thunder Jet sends a force to overthrow Garer, new emperor of Kingdom Go-Jo. The front fleet commanded by Cobin, the son of Colin the pirate, surround the first target, the great fortress of Gen-Bookan. The fortress has the gigantic cannon and It is too dangerous for Cobin's fleet to get closer. Emperor Garer orders his brother, Gasan, to destroy T.J. Sishin prepares a secret operation for the purpose of a short decisive battle. His idea is to plant the rocket engine on a huge meteor and clashes it to the fortress. His operation goes well and the fortress is destroyed. T.J. charges into Gasan's command ship and slashes him down.