Prologue wa Shumatsu de

"For over twenty years, the Professor secluded himself underground, driven by a desire for revenge against humanity. Finally, he completed his ultimate humanoid weapon: Unit A-00GR. However, when they finally emerged to the surface, they found the world already in ruins. Amidst the collapse, Unit A-00GR and the Professor travel through the wasteland, exploring the lingering 'emotions' of mankind."