Those incompetent aliens are still plotting to conquer the Earth! The only obstacle in their path is the giant, feminine robot ARIEL! But the young pilots have lives of their own... When Kazumi receives a mysterious love letter from a secret admirer, should she cancel her first date just to save the Earth?

The new frontier of Venus has degenerated into a dystopia ravaged by the civil war between Ishtar and Aphrodia. Bubbly reporter Susan Sommers arrives in the capitol of Aphrodia just before it's captured by Ishtar. She falls in with a bunch of teen-agers who live for a sort of motorcycle version of Roller Derby. Daredevil rider Hiro and his friends reluctantly join the struggle to free Aphrodia from the invaders. Not surprisingly, Hiro proves an ace at piloting the mono-cycles that are the Aphrodians' secret weapon in the key battle.