Before she was named Nana by the French couple who adopted her as a child, she was Esther Pak, a girl growing up in a Korean orphanage. And before she was Esther Pak, she was Munju, a small child abandoned on the railway tracks in Seoul.

Nana has no memories of the first three or four years of her life, no family records detailing the personal information of her parents, no birth certificate or any medical records from the hospital where she was born. She was abandoned on the railway tracks at a station in Seoul, where a train conductor saved her life and took her in for a year, before bringing her to an orphanage.

Adopted by a French couple, she is now a playwright in Paris. The day she finds out she is pregnant with her first child, she receives an email from Seoyeong, a Korean filmmaker who wishes to make a documentary about her life. Nana accepts the offer, hoping to reconcile with her past as she prepares to become a mother. She travels to Seoul stays at the filmmaker’s apartment. One night, during a power outage, Nana ventures to Bokhee’s Kitchen, the restaurant on the ground floor, and befriends the woman who runs it. Soon, they develop a strong bond. But while Nana moves through Seoul, visiting the orphanage and the train station where she was abandoned thirty-five years ago, the woman everyone calls Bokhee has a stroke and is hospitalized—and her real name and past come to light.

Simple Heart is a poignant and tender novel that delves into the lives of women from postwar to present, the bonds of love between women and children, and the difficult choices mothers have to make.