When tunnel excavation work ensues near Mt. Konpo for the new Tokai Super-Expressway project, a large, strange stone is found. After a worker claims to have seen a huge monster, a young scholar recalls the legend of Gomess, a fearsome beast, and a phoenix-like bird, Litra. When Yuriko and Jun get trapped in the caverns, they hear a rhythmic beating from the stone and discover the legendary Gomess.

While investigating an undersea volcanic eruption, Jun and Yuriko witness the splashdown of a Mars Exploration Probe. Recovered by the Space Development Agency, they find strange images and two golden spheres inside the capsule. They jokingly conclude intelligent beings on Mars returned the capsules and gifted them the spheres, but after a thief steals them, a monster named Namegon is unleashed.