Neo Empire Gear was originally established at the South Pole by the rogue scientist Hideo Kageyama, after he converted himself into a cyborg and took up the name "Doctor Man". Seeking to create a technologically-advanced empire to rule of the Earth, Doctor Man created an army of machines to assist him in his conquest, keeping his true origins a secret from them and everyone else. To command his army, Doctor Man created a trio of humanoid robots named the "Big Three". From their Neo Grad fortress, the Gear plot attacks across the world to further their goal of global domination.
While initially opposed by the Biomen, the Gear later face another opponent when Bio Hunter Silva arrives on Earth in search of his mecha Balzion and battles both the Gear and the Biomen. The Gear initially try to ally with Silva and he refuses, after which the Gear being plotting to seize his mech Balzion for themselves. Eventually, most of the Gear's generals were killed off by Silva before Doctor Man was defeated by the Biomen in the finale.
- Doctor Man - Leader
- Big Three
- Mecha Gigans
- Neo Mecha Gigans