The enormous mecha lay on the ground, the mechanical structure on it continuously erupting with sounds as loud as a volcanic eruption, yet there seemed to be some internal malfunction, preventing it from standing up again.
Hundreds of kilometers away at a military base, a group of people were tensely watching dozens of display screens in the operations room. Not only this area, but hundreds of cities worldwide were under attack from these gigantic creatures.
Red signals kept flashing on those screens, indicating extreme danger. Even though humans worldwide had prepared the most comprehensive alert system for a massive monster invasion event, the opponent's strength still exceeded their imagination.
Hundreds of years ago, during another spatial experiment, humans in this world unintentionally opened a portal to another world. Although the experiment was promptly closed, a gigantic terrifying creature over 200 meters tall still came through to the human world through that portal.
