In a world once ruled by Dragon Tribes and Giants, now dominated by Humans besieged by grotesque Aberrations known as the Hour of Ruin, a young man named Madarame Kurato suddenly finds himself transported from modern Japan into the cockpit of a ten-meter-tall magical knight called Clawsolas. This giant knight is operated jointly by a knight controlling the mecha and a mage managing its magic furnace. Kurato’s consciousness takes over the knight just as the original pilot, Dino, is knocked unconscious during a desperate battle against a large Disaurs. The mage Revia, Dino’s childhood friend and partner, is about to escape using a teleportation stone when a crack prevents her from activating it. An unknown voice fills her mind, and the seemingly immobile Clawsolas rolls aside to dodge the monster’s bite. Revia senses a new presence through the magic circuits, one that synchronizes perfectly with the mecha. Kurato, confused but instinctively drawing on his family’s Taisha-ryu swordsmanship training, kills the large dinosaur with precise, clean strikes, shocking the soldiers around him.After the battle, Kurato emerges from the knight to find himself in a medieval-style military encampment. The language of this world is incomprehensible at first, but through the consciousness link with Revia, his language center receives knowledge, allowing him to communicate. Revia learns that Kurato is a Rare Human, a lost soul from the Horizon of Causality, a term for those who mysteriously appear from other worlds. The captain, Xenos, a stern but boisterous knight, agrees to take Kurato in after he proves his skill. However, the original pilot Dino is enraged at being replaced by a stranger and challenges Kurato to a duel. Using his superior swordsmanship, Kurato disarms and defeats Dino without killing him, earning the respect of the unit and officially becoming the knight of the Clawsolas Fourth Unit, with Revia as his mage partner. Dino is demoted to re-training under Captain Xenos.Kurato learns that the giant knight technology was brought to the continent by a Rare Human, Nina Valer, lord of the Zephyrus Domain. This innovation gave hope against the Aberrations, which are large monsters that appear alongside swarms of smaller ones. The unit’s current mission is to destroy a Spirit Gate that the Aberrations are constructing. Kurato, despite his inner reservations about using his battle swordsmanship in a real lethal world, decides to join the expedition, reasoning that he has no means to survive alone in the dangerous wilderness with unknown flora and hostile magical beasts. He shares a tent with Revia, which embarrasses him, but she treats the arrangement as practical. During their first evening, they exchange formal introductions: Revia Lumias, a wind and fire mage, and Kurato Madarame. He bombards her with questions to understand the world. He also learns that Rare Humans often face great hardship or death if they cannot communicate, so his ability to speak the language is a blessing. As the encampment prepares for the next day’s march, Kurato resolves to leave his hesitation behind the blade, embracing his role as a warrior in this strange land. The story sets up his initial integration into the military unit, his partnership with Revia, and his acceptance of the dangerous mission ahead, while exploring the personal conflicts between him, the displaced swordsman, and the former pilot Dino, who struggles with his loss of position and the shame of defeat.
