Warm It Was That Winter 1984 on netflix

With the outbreak of the Korean War, Su-ji and Oh-mok lose their parents. Along with their brother Su-cheol, they go live with their mother’s parents. As they go to take refuge, Su-ji loses Oh-mok by accident. Time passes and with her older brother Su-cheol’s success, Su-ji enters the high society. But due to the guilt of losing her younger sister Oh-mok, she does a lot of charity work constantly looking for Oh-mok. When Su-ji finally finds Oh-mok in an orphanage, she turns coldly away from Oh-mok for not having any evidence to prove that she is her sister. Oh-mok marries Il-hwan whom she has met at the orphanage and they live a hard life. Finally, Su-ji is convinced that Oh-mok is her sister but after living through such hardship, Oh-mok breathes her last.