(plot:At the Godzilla Countermeasures Center in Tokyo, Dr. Zenji Shida advances the idea that Godzilla and Anguirus lived in a hollow earth cavern before emerging to menace Japan. In the event of Godzilla's unthawing after the events of Godzilla Raids Again, he has invented a giant humanoid robot, the Bride of Godzilla, to combat him. He also showcases Eve, a human-sized robot with advanced A.I,our girls seemed to try to question it.

An enormous blood-sucking flea menaces a village outside Kyushu. Zenji's brother Yoshi, in charge of the mining company there, leads a team to kill it. They bring in Dr. Yanai, a former colleague of Dr. Shida's to examine his remains. A reporter startles Yanai by pointing out that Eve closely resembles his wife Riko, who chose him over Zenji years ago. Yanai, a Christian, believes that Zenji is tampering in God's domain with his creations. Riko visits Zenji's laboratory after hearing the news, and is stunned by the sight of Eve and a "foster daughter" robot named Riko, though she eventually has an amiable meeting with the latter. Back in Kyushu, miners discover an underground cavern just as Zenji predicted, containing a second Anguirus, a giant bat, and a family of mermaids. They flee as Godzilla bursts out of a lake and tell Yoshi their story. He agrees to call in Zenji, but an earthquake suddenly seals the entrance to the cavern. Following a mermaid sighting, they realize there is a second, underwater entrance. After watching the mermaid family battle a giant octopus, the robot Riko follows them home and charms them with a dance. She finds still more creatures in the cavern: a giant Archaeopteryx and chameleon. Though she tries to befriend him too, Godzilla swings at the cliff she's standing on, causing her to fall into the water below. The mother mermaid returns her to Zenji, with a JSDF diver rescuing her and Riko from a sea serpent along the way.

With Godzilla's return to Japan imminent, Zenji downloads Riko's memories into the Bride of Godzilla. The machine's unclothed body resembles that of the human Riko's, while she possesses the machine Riko's face. The monster attacks Wakamatsu Port, along with Anguirus and the chameleon, while the Archaeopteryx rises out of the mine. Godzilla destroys a church Yanai was hiding inside, killing him, though Riko survives. As a power plant charges up the Bride of Godzilla, the JSDF dispatches fighter jets against the monsters. They manage to kill the chameleon, but are no match for Godzilla and the Archaeopteryx,our girls attempt to hold them off until The Bride of Godzilla activates and promptly kills Anguirus by tearing out his throat, then impressing Godzilla by shrugging off his atomic breath. After she breaks the Archaeopteryx's neck, he sets it on fire in a display of affection. Shida announces that a wedding of sorts is imminent, as "it is the foreplay of love to be beaten." Monster and robot continue battling underwater, with Godzilla's ray creating another entrance to his subterranean home. They enter the cavern and embrace before the Bride detonates a hydrogen bomb Zenji planted inside her,our girls can only describe it as a beautiful firework show.

Zenji tries to make amends with the widowed Riko, but she rejects him again. As the mermaid family surfaces, they can only watch as a frightened soldier shoots the child,our girls hear the sound of rumbling from beneath their feet,and out came a unfamiliar nightmare,Godzilla,who musters continuous, earth-shattering roars.)(it needs a script with dialogue,music cues for this alongside sound cues from audio)