Autumn Fairy tale (Autumn In My Heart)

Synopsis:
The story begins during the teenage years of the two main characters: Yun Jun-suh (played by Choi Woo-hyeok) and Yun Eun-suh (played by Mun Geun-yeong). They both came from a rich industrialist's family and believed they are brother and sister by blood, until their parents discovered the truth after Eun-suh was involved in an automobile accident.
After blood tests were carried out by the doctor, it turns out that Eun-suh belongs to another parent, and Choi Shin-ae (played by Han Chae-yeong), belongs to the Yun family. At first, only the parents of Shin-ae and Eun-suh knew about this, but eventually, Shin-ae discovered the truth after she got into a fierce argument with her non-biological mother over gifts she received from Shin-ae's biological father. Eun-suh only discovered the truth after Shin-ae, now kicked out of the Choi residence, wants her biological parents to take her in. In the end, the two daughters were returned to their rightful parents. Eun-suh now lives with the Choi family, whose biological father have already died and her widowed mother operates a small food stall and lives in abject poverty.
Years went by, and in the duration, the entire Yun family went to the United States, where Jun-suh (now played by Song Seung-heon) returns to South Korea as a successful artist. He went back to the town he lived in, where he encountered his old friend, Han Tae-seok (played by Won Bin). They both resided in a hotel where Eun-suh (now played by Song Hye-gyo) works as a telephone receptionist. Tae-seok (who doesn't know about the entire brother and sister mixup that happened earlier) fell in love with Eun-suh and played games with her until she was terminated from the hotel she worked at. One day Eun-suh saw Joon-suh and followed him to the beach where he was with Yumi and Tae-sok and the two "siblings" finally met after ten years.
Both Eun-suh and Joon-suh pretended to have more of a sibling relationship in front of others at first but Shin-ae - angry at Eun-suh for taking away Tae-sok - exposed the two after she found a love letter Eun-suh had written for Joon-suh.
As a fight between Jun-suh and Tae-seok grows over their professed love for Eun-suh, she discovers she has leukemia (the same illness that took her biological father's life). She didn't tell anyone what happened until the disease was at a terminal stage. All hope was lost by now, and Eun-suh died as Jun-suh was carrying her around the beach for sightseeing.
Before Eun-suh died, she told Jun-seo not to follow her in death, and to continue living. However, Jun-suh, grief-stricken by the death of his lover and "sister", allowed himself to be struck by a truck (ironically the story starts with Eun-suh being struck by a truck), and he died shortly afterwards.

Trivia:

Autumn Fairy Tale (also known as Autumn in my Heart) is the first installment of the four part Endless Love drama series produced by South Korean TV Network KBS. It was produced in South Korea in 2000.