There's this pub (Izakaya) called "Gen" that was supposed to be in a certain place in the Kanto region of Japan. After opening the door one day, it was found to be connected to the city of Parisia, the Capital of the Eastern Kingdom Oiria. Individual residents from a foreign world such as crestfallen monks, warriors, noble female chevaliers, daughters of noisy famous aristocrats, etc. All visited the peculiar izakaya which they've never seen before, and gradually they'll become fans of the dishes.