Haruto Sato was an ordinary manager in a mundane world, his life defined by the monotonous grind of work and a growing sense of emptiness. But everything changes when he is suddenly struck by a speeding truck—Truck-kun. In the void between life and death, Haruto meets the Supreme God of the Omniverse, who reveals that Haruto's death was a cosmic mistake. The truck was meant to eliminate a future threat to Earth, but Haruto was accidentally caught in the crossfire. To atone for this error, the Supreme God offers Haruto a second chance: a new life in a fantastical world of magic, dragons, and demons. Reborn as the son of a powerful union—his mother, the sister of the Demon Emperor, and his father, a mighty dragon—Haruto inherits both a demonic and draconic bloodline. But his extraordinary rebirth doesn’t stop there. As a final gift, Haruto is granted a powerful "Sign-In System," which will bestow upon him incredible abilities as he grows. On his first sign-in, Haruto receives the strongest body in the world, perfectly attuned to his unique bloodline, and a rare potion that strengthens and harmonizes his demonic and draconic heritage. Now, in a world where power is everything, Haruto must navigate his new life, unlocking the potential of his dual bloodlines and rising to become a force to be reckoned with. But as he grows stronger, he will discover that his new world harbors ancient secrets and formidable enemies that could threaten not only his life but the balance of the entire multiverse.