In 11941 AD, the YoRha group went to Earth during Operation Pearl Harbor to take the planet back to the mechanical forms of life that invaded it. Only four members of the squadron arrived on the ground. Although they had asked for the mission to be cancelled, the command centre ordered them to continue. In a battle against the enemy, resistance fighters who arrived on Earth hundreds of years ago came to their aid. First distrustful of the YoRha, they ended up collaborating to carry out the operation, understanding the problems of each one.