In a world where gates suddenly appear and monsters emerge from them, hunter Yoon Min-jun lives burdened by guilt after losing his girlfriend, Jung Si-a, in a gate break incident. One year after her death, on the anniversary of the tragedy, another disaster occurs at her grave… but this time, what emerges from the gate is not a monster. It is Si-a herself. The girlfriend he thought was dead has returned, but no longer as the person he once knew. She has become a dragon, the strongest living creature, and after spending an unimaginably long time searching for a way back to him, she now wants only one thing: to stay by Min-jun’s side… and make sure he did not find another girlfriend while she was gone.