Shipwreck survivors are found on Infant Island, an island previously used for atomic tests. Amazingly free of radiation effects, they believe they were protected by a special juice given to them by the natives. A joint expedition of Rolisican and Japanese scientists explores Infant Island and discovers many curious things, including two women only a foot high, the Shobijin. They are taken from the island, which only awakens the giant moth that wreaks havoc on Japan.