Somewhere in the space, there were robotic aliens called "Offendrons". They attacked and colonized other planets to get the energy source they need for living.
In the year 3045, Offendrons has arrived at the Solar System and invaded the Earth, to build their 255th colony. Within a year the Earth had successfully taken by Offendrons.
However, the mankind didn't give up. Some people escaped to the base on Mars and developed a virus that turns Offendrons into a brainless killing machines that can only think about destroying other Offendrons.
3 years later, humans started their revenge with countless amount of war drones and space fighters. When the fate of Offendrons came to a crisis, the Offendron Warriors—those who are capable of greater firepower and transformation for various combat situations—has appeared to save their own kinds.