The female lead is a young girl in her early 20s. She got pregnant but the guy didn't want to take responsibility, so she runs away. She accidentally ends up on a train where she meets the male lead's twin brother and his wife who is also pregnant. The train wrecks and the couple dies. The female lead wakes up in the hospital to find out that it's been assumed she's the wife. So his rich family takes her in and she falls in love with the male lead. (Source: MyDramaList)