2,000 years ago, the People of the Fourth Planet lived in a modern world where robots and other advanced technologies did their works but as time passed the People of the Fourth Planet became lazier due to endless luxuries provided by their technology, thus making the robots rebel and take control of their planet with the Robot Chief, becoming the planet's and oppressing the humans (e.g. if a person was involved in a hit-and-run accident, the victim will be listed as the culprit).
On Earth, Dan and Soga of Ultra Guard were sent to test a new rocket named Scorpion, which could travel out of the solar system. They rode into the rocket and blast off while falling asleep. However, a malfunction they found themselves on a planet which they believed to be Earth. As they explored the planet, they saw a gas station and a harbor but with different logos. Spotting a public phone, they tried to contact the TDF but to no avail. Then, they notice a boy on his bike as he almost gets run over by a truck by the Robot Commissioner with a cigar in his mouth. Dan tried to tell him that the boy was almost ran over but he said that boy should've been more alert. Then the man had them arrested and escorted them to a building, where they talked to the Robot Chief. As they walked they notice that a studio was making a gangster movie. The military man brought them to their leader, the Robot Chief where he explained the planet's history while scolding his assistant, Ali, for a different taste of coffee.
After the conversation, they sent Dan and Soga away while the woman slipped a note on Dan's helmet, written on it was "They're going to kill you. Flee! Your Earth is in danger!". As they got to the movie studio Dan realized the human actors in the gangster movie were really killed because the robots used lived rounds. The robots did this as a punishment for them due to their political involvements and to make the movie look lively.
While the Robot Chief and the Robot Commissioner let their guard down, Dan and Soga made their escape with the help of the Robot Chief's assistant as she tried to hide them among the other Fourth Planet humans but instead getting her and a man caught and dragged away for execution. Just as it was about to begin, Dan and Soga lead an attack but get caught themselves. Dan quickly changed into Ultraseven and destroyed the whole building along side the Robot Chief and the Robot Commissioner. He then destroyed all of the Fourth Planet invasion armies and the robots. Dan and Soga finally liberated the Fourth Planet and went back to Earth safely. When they got back, the rest of the Ultra Guard never believed their story, thinking it as a dream they received during their space hibernation.
- Ali (Robot Chief's assistant): Machiko Ai
- Ali's little brother: Kozaburo Onogawa
- Unnamed man whom protected Ali: Katsuaki Kawada
- Despite being a race of humans, they are counted as aliens due to living on the Fourth Planet and not Earth.
- They were renamed the Humans of Simulon by the TNT dub.
- Height: Same as human
- Weight: Same as human
- Origin: Fourth Planet
- Powers and Weapons
- Intelligence: The People of the Fourth People were smarter than normal humans, as they were capable of building advanced robots and machines.