Journalists Ichiro Sakai and Junko Nakanishi cover the wreckage of a typhoon when an enormous egg is found by local villagers. The pair joins up with Professor Miura and discover that the egg has been sold off to Mr. Kumayama of Happy Enterprises. Backed by the greedy Jiro Torahata, the businessmen seek to commercially exploit the egg. Mothra's fairies soon arrive and are aided by the journalists in a plea for the egg's return to Mothra and Infant Island. As their requests are denied, Godzilla emerges from the typhoon wreckage and heads toward Nagoya. Having lost their good will, Sakai, Junko, and Miura must make a plea of their own to Mothra and the people of Infant Island to help save Japan from Godzilla.—Mosura
Mothra's egg washes ashore and is claimed by greedy entrepreneurs who refuse to return it to her fairies. As Godzilla arises near Nagoya, the people of Infant Island must decide if they are willing to answer Japan's own pleas for help.