Otoño en mi corazón

Jun Seo and Eun Seo are a brother and a sister who grew up in a happy and wealthy family. Sin Ae grew up in a tough life with her mother, who runs a restaurant, and she is always jealous of Eun Seo, who has everything she wants. When she bullies Eun Seo out of jealousy, she is scolded by Jun Seo. Eun Seo is hospitalized after a car accident one day, and the truth is disclosed that Eun Seo is not the biological daughter of Professor Yoon's couple. Eun Seo leaves Professor Yoon's couple to find her birth parents, and Professor Yoon's family leaves for the United States. As an adult, Eun Seo works at a hotel. She runs into drunken Tae Seok, the son of the CEO of the hotel, and Tae Seok falls in love with Eun Seo. However, Eun Seo and Jun Seo fall in love with each other after they are reunited as adults. What will bring from the heartbreaking love and separations between these four people?