Believing that 21st-century Seoul, where there is no class discrimination, is the authentic 'Yuldo-guk' of his dreams, Heo Gyun begins his chaotic adaptation at the grumpy Eunsil's small diner.

Heo Gyun saved Eun-sil's mother's life, but his identity is unknown and he is suspected by the police... Eun-sil, who can't cook, is in danger of having to close down her restaurant...

Heo Gyun, who is a genius even in cooking, seems to agree to Eun-sil's suggestion to open a restaurant together, but he is not sure if he will accept her offer... In the meantime, Heo Gyun is confused when he meets Mi-sol and an old woman who look just like his acquaintances in Joseon.