A greedy developer unwittingly hatches a gigantic baby moth upon Tokyo, while Godzilla strikes once again. A hurricane blows Mothra's egg off Infant Island and causes it to drift to Japan. Banzo Torhata sees an opportunity to make money off the egg but Mothra's twin priestesses show up and plead with him to return the egg or else the larva will hatch and cause great damage in search of food. Torahata refuses and tries to kidnap the fairies. They then go to reporters Ichiro Sakai and Junko Nakanishi to try to persuade Torahata to return the egg. Torahata still refuses and the girls leave with the adult Mothra. In the meantime Godzilla reawakens and begins another rampage. Japan's only hope is for Mothra to return and not only save her unhatched offspring, but Japan as well.