It was supposed to be an eternal battle of reincarnation that would be repeated over and over again. The brave Riona defeated the Demon King and was reincarnated in modern Japan in order to manifest the next Demon King! As the only daughter of an inn, she was supposed to be freed from her destiny as a hero and spend peaceful days without the Demon King, but the inn is in a big pinch because of the luxury hotel across the street. Meanwhile, due to a certain incident, she meets the hotel owner, but that person turns out to be the demon lord she thought she would never meet again. A reincarnation love story between a former hero and a former demon king...?