Sergeant Keroro and his team of four extraterrestrial soldiers descend from planet Keron to Earth with conquest in mind. Yet, unexpectedly, they find themselves embracing the human way of life. Assigned to befriend Hitana for their mission, Keroro instead forms a close bond with her son, Fuyuki. Amidst their routine of Gundam model shopping, a chance encounter with a shrine leads to a fateful accident—an ancient vase shatters. Soon, eerie events grip the town, sparking fear among its residents. Within the shattered vase lies Kiruru, a formidable weapon of Keron's past. As Mirara, the keeper of Kiruru's secrets emerges, a daunting task to safeguard Earth unfolds, setting the stage for a perilous journey ahead.