Een vrouw stapt in een vreemde machine en wordt... een kipnugget?! Nu is het aan haar vader en bewonderaar om een ​​gekke zoektocht te ondernemen om haar terug te brengen.

After the murder of Luna, the robot society that rules the planet starts to rust and decay. Death and despair spread through the land like wildfire. The only one unaffected by the affliction that becomes known as "The Ruin" is Luna's assassin, Casshern. Unable to remember if he really triggered this capital sin against the entire mechanized civilization, Casshern embarks on a journey to unravel the mystery that connects him, Luna, and the plague.

Dr. Azuma creates robots to benefit mankind, but they unexpectedly rebel and begin to destroy everything in their paths. To deal with the catastrophe, Dr. Azuma's son volunteers to become a human robot, even though he knows he will never be able to return to human form again. He confronts this grave situation to ensure a bright future for all humans.

We have been colonised by the machines we have built. Although we don't realise it, the way we see everything in the world today is through the eyes of the computers.

Far in the future, ecological disaster on Earth led humans to create a race of androids called Neoroids to clean up the mess but they promptly turned on their human masters and enslaved them. Enter a lone fighter named Casshan with a mission to free humanity ... and restore his family's honor.