A wealthy businessman visits a mining area to purchase ore and unexpectedly discovers an abused female laborer. The sole of her foot bears a distinctive crescent-shaped birthmark identical to the one belonging to his long-lost daughter. He notices that the daughter who has lived in his home for three years is acting strangely and deliberately concealing the soles of her feet, leading him to suspect that she is an impostor. While the impostor enjoys the luxurious life of a wealthy family, his biological daughter suffers unimaginable hardship at the mine. He secretly arranges an investigation, determined to expose the conspiracy behind the identity swap and bring his biological daughter home.