Terrestrial Defense Force presumed that incidents of human dissapearing is done by alien, and sent out the elite team "Ultra Guard" for investigation. However, a mysterious wanderer appeared in front of Furuhashi and Soga, the members of the Ultra Guard. The man named himself Dan Moroboshi, warned them about the danger and told them how to solve the incident. Who actually is this man?
Ultra Guard member Ishiguro is back from Space Station V3. Dan sent him home and found Tilsonite 808, something that does not exist in Earth, in Ishiguro's yard. That night, incidents of people being attacked happened one after another. What is the relationship between the incidents and Tilsonite 808? At the same time, Ishiguro's wife notice something wierd about her husband.
Dan and Furuhashi headed towards Kisodani for investigation of a mysterious object that felt down. The obeject was found out to be a spaceship, and a girl from the spaceship stole Dan's Ultra Eye. Monster Eleking appeared in the lake nearby, and Dan summond Capsule Monster Miclas to fight against it, but Miclas was no match for Eleking!
Nuclear Ship Max, the most advanced scientific research ship of TDF, went on investigation of the serial ship disappearing incidents. However, NS Max disappeared as well! The vanished ships were sent into space by Alien Godola, as a part of its Earth invasion plan. When Dan figured out Alien Godola's disguise, he was locked into a capsule.
World famous scientist Professor Yushima came to Japan, on a trip to attach the Yushima Diode to the TDF Far East Base. However, Professor Yushima has already been brainwashed by Alien Vira! Dan noticed the fact earlier than anyone else, but nobody believed in him. Instead, Dan was retrained. Who will help Earth out of the danger?
A black shadow appeared in Anne's private room. The shadow told Anne that he was an alien, but had no intention to harm humans. At the same time, a message was sent from Outer Space City Pegassa, saying that they had a system trouble and claimed Earth to change its orbit. If it was not done, Peggasa City would clash with Earth!
A mysterious monster appeared and attacked citizens one by one. The criminal was identified to be the atrocious criminal 303 from Planet Quraso, who broked the prison of his home planet and escaped to Earth. To protect the citizens, Ultra Guard enforced their system of surveillance. However, Alien Quraso stroke back with a clever scheme!.
In Kitagawa-cho, reports of violent cases increased rapidly without reasons. At the same time, an airplane crushed and the pilot is also from Kitagawa-cho. What is happening in the town? Ultra Guard starts investigating, until the members sent to investigation also became voilent. The most likely reason might be the cigarettes.
One night, Furuhashi is attacked by a mysterious woman during patrolling. Seemingly her real target is Dan Moroboshi. But why would she do that? During an investigation, Dan meets an old man who sells toys. Is this old man related to the woman? Dan figures the true identity of them both.
Akira, a boy who is close to the Ultra Guard member Anne, found his neighbor acting suspicious. After receiving the report, Anne went to Akira's house with Dan, where she witnesses Dan disappearing in front of her! Where is Dan? The answer is the forth dimensional space. Dan has to find a way out!