Choushinsei Flashman
In 1966, 5 young 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 5 children were rescued by Mess' archenemy, the Flash alien race, which took each one to a different planet of the Flash solar system for training. Each child was trained separately in a range of superpowers that will allow them to fight Mess, their bodies also adapted to the atmosphere pf 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.