A GF Commander is a person who collects and battles with Gotcha Borgs. All of the characters in Gotcha Force are GF Commanders.
GF Commanders team up with Gotcha Borgs, who convert their commanders' courage into battle energy called GF Energy. As a GF Commander continues to win battles with Gotcha Borgs, his GF energy will continue to increase. The age of GF Commanders varies, though Kakeru implies near the end of the game that there are no adult GF Commanders.
Most GF Commanders are on the side of the Gotcha Force and fight for peace, though there is also a Death Force counterpart of a GF Commander called a Death Commander. Other GF Commanders can be unaffiliated with either side.