Ninja Senshi Tobikage

Ninja Senshi Tobikage is a mecha anime by Studio Pierrot. It was adapted as Ninja Robots in the United States.

Plot
In the 23rd century, earthlings have colonized Mars and the Moon. Much like convicts in Australia during the 18th and 19th century, the settlers of Mars consist mostly of convicts from Earth. The Martian colony is run by military dictator Hazzard Pascha, who tests every settler on whether they should serve in the military or become a labourer.

Joe Maya is a 16-year-old who lives on Mars with his father. His dream is to return to Earth. He has two friends Mike Coil and Jenny Ai (Reni Ai in the Japanese original). During an escape from Martian military police, Joe and Mike stumble upon a crashed spaceship, the Xenos 5 (the El Shank). Inside, they encounter three human-looking aliens: Princess Romina, whom Joe instantly finds attractive, her willowy attendant Jade (Shaf), and a young red-headed general named Icelander (Irbora). But before they can converse, a group of robots land and attack the spaceship. As the three aliens hide, Joe jumps into a machine, but it turns out to be a ninja robot named Black Lion. The battle leads outside the ship where a mysterious ninja robot Cybertron (Tobikage) suddenly appears. It wipes out several of the enemy robots before it merges with Joe's robot, which transforms into a mechanical lion that eradicates the remaining attackers.

After the attack, the aliens adjust their translators and communicate with Joe and Mike. They are from the planet Ladorio (also romanized as "Radorio"), and are in a war with the Zaboom army. They convince the boys and Joe's friend Jenny to help them out because the three teenagers are the only humans who have the innate ability to operate their ninja robots. The teens agree as it gives them a chance to escape Mars and go to Earth. Along the way, they make new friends and sometimes re-open old wounds, while Cybertron looms mysteriously in the background.