Crown Prince Lee Gak’s life was turned upside down when his beloved princess drowned under mysterious circumstances. Determined to uncover the truth behind her death, he embarks on a quest with his loyal yet comically inept retainers. But fate has an even bigger surprise in store as Lee Gak wakes up 300 years later far removed from his royal palace—in modern-day Seoul, a world of smartphones, subway cards, and fast food. Stranded in this chaotic new era, he must impersonate his own doppelgänger, a missing chaebol heir, all while enduring constant bickering with Park Ha—the housemate who has no patience for royal drama but may hold the key to his heart. Amidst the confusion, Lee Gak meets Joo Se-Na, a spirited woman who looks exactly like his late princess, sparking unexpected emotions. As past and present collide, Lee Gak and his quirky entourage unravel long-buried secrets that threaten not only their futures but the fate of those they love.