“Dummy Mommy” is a story about a tale of love, conflict and reconciliation between three women of different generations. Kim Young Joo, a genius with an IQ of 200 and the youngest editor of a leading fashion magazine, is constantly embarrassed by her dim-witted mother, who has an IQ of 56. Ashamed of her mother’s intellectual disability and suffocated by her affection, Young Joo runs away to get married and leaves her mother behind. Young Joo, in turn, gives birth to her own daughter and finds herself in a different position.