Three years have passed since Kikaider defeated the DARK. A thunderstorm heralds the appearance of Hakaida, now possessing the brain of the deceased Professor Gill, followed by Red Hakaider, Blue Hakaider and Silver Hakaider. They are after a young boy who is the key to a secret that will plunge the world into darkness. When the Hakaider Force attacks, Kikaider 01, the android of justice, goes into action to challenge them!