Choushinsei Flashman

In 1966, five children were kidnapped by an alien group known as the Alien Hunters for the Reconstructive Experiment Empire Mess, who wanted samples of humans from Earth to experiment on. The children were rescued by Mess' arch enemy, the Flash alien race, which took each one to a different planet of the Flash solar system for training. Each of them was trained separately in a range of superpowers that will allow them to fight Mess, their bodies also adapted to the atmosphere of the Flash Solar System making them gain special abilities. When they finally return to Earth in 1986 to combat Mess, who is now trying to invade it, they use the opportunity to search for their birth parents. They later learn that their time on Earth will be cut short as their birth planet's atmosphere has become deadly to them and after a year, they will die from what is known as the Anti-Flash Phenomenon.