该剧取材于韩国最早民间故事集《於于野谭》中歙谷县令金聃龄（李敏镐饰）将被渔民捕获的人鱼放归大海的人鱼传说。讲述数百年之后濒临灭绝来到都市里的人鱼沈清（全智贤饰）适应陆地生活和天才骗子许俊宰（李敏镐饰）重逢并陷入爱情的故事.A county magistrate's plan to release mermaids into the ocean backfires when they're caught by fisherman.
