Intruder

About Intruder: Seo-jin is a widower still grieving his wife's death. Then he receives the news that his long-lost younger sister, Yoo-jin, who went missing 25 years ago, has turned up. Unlike the rest of his family, who welcome her into their arms, Seo-jin feels that Yoo-jin is a stranger.

Long gone sister came back as a stranger.