In the closing days of WWII, a Japanese soldier afflicted with tuberculosis is abandoned by his company and left to wander the Philippine island of Leyte.
Gamera escapes from his rocket enclosure and makes his way back to Earth as a giant opal from New Guinea is brought back to Japan. The opal is discovered to have been an egg that births a new monster called Barugon. The creature attacks the city of Osaka by emitting a destructive rainbow ray from his back, along with a freezing spray capable of incapacitating Gamera.
Yuko is sent to the coastal regions to be raised away from the rest of her sophisticated family where she finds out from her ill grandmother that she is not who she thought she was.
