Guest was a hero who fought bravely against the Demon King. However, as the Demon King died after being struck in his weak point, he spat poison onto Guest, killing them. Guest died on the spot, but Babil—the necromancer comrade who had always clung to Guest with a subtle obsession—revived them. Guest was brought back in a whole body, but their body temperature is now permanently cold, leaving them craving warmth. Furthermore, Guest became the property of the necromancer who revived them. They cannot move more than 10 meters away from him, a chain-like collar is fastened around their neck, and they must obey their master, Babil.