One day, the close friends Natsumi and Keroro went out together to buy Gundam plastic models. Unexpectedly, on their way home, they accidentally stumbled into a mysterious small shrine. While Natsumi was thrilled by this ancient civilization site, Keroro carelessly broke a pot-shaped object. Immediately sensing an ominous premonition, the two hurriedly turned and ran home. Soon, the mark "╳" appeared on Keroro and Natsumi's faces. As time passed, people around them also began to develop the "╳" mark on their faces. Those bearing the mark seemed to possess psychic powers, able to make others develop the "╳" mark at will. This incredible yet convenient ability was greatly favored by humans, spreading rapidly in the blink of an eye. At this time, an alien named Mirara appeared and explained that the "╳" mark was an ancient weapon called Kiruru, which would absorb human negative energy and destroy Earth. However, since the "╳" mark hadn't caused any negative effects, Natsumi and the Keroro Squad didn't take this warning seriously. Later, Kiruru began to grow enormous, and the "╳" mark started spreading negative energy. Humans panicked, growing distrustful of everyone around them. Seizing the opportunity, Keroro decided to use this psychic power to launch an invasion of Earth. As Kiruru absorbed human negative energy, its size gradually increased, and it began destroying the streets. Feeling powerless against all this, humans could only watch helplessly as everything was torn apart. If things continued this way, would humanity face extinction?