Kimi no Tame ni Dekiru Koto (1992)

Seon Woo receives calla every morning and wants to find out who the secret admirer is. One day, he goes to a nearby florist’s where he meets Ji Hee. He falls in love with her at first sight, thinking she is the one who is sending him flowers. Seon Woo asks Ji Hee to go on a date, and she agrees. He arrives at the rendezvous only to find that Ji Hee is held hostage and, to his horror, killed before his eyes.

Tatsuya was killed in a car accident and his spirit lives in Hikata - the one who killed him in the accident. Since then, he had a hard time trying to change his girlfriend's perception of "him" or "Hikata" while still trying to protect her.