Her Heart Beats in its Cage: Hong spent ten years in prison for killing her husband. Thanks to her contribution to the prison art workshop, she receives an unexpected opportunity to reduce her sentence. Her son, Lele, was raised by his grandmother and was never prepared to live with his mother. After their reunion, Lele always treats her coldly. Faced with a lonely grandmother who longs for Lele to return to her and a society that treats ex-convicts poorly, can Hong escape her invisible prison and regain happiness?