Regret (1969)

Dr. Go, an authority in botany, lives in Buldang Village. His house is haunted by the ghost of Ok-nyeo, who has loved his friend, Choe Seong-ho. She has been killed unjustly, and the ghost comes to Dr. Go every night, asking for fresh blood from young women. One day, Jeong-ju, the daughter of Choe Seong-ho and a student of botany, comes to the region with boyfriend Chang-il to collect samples. Dr. Go is possessed by Ok-nyeo and tries to kill Jeong-ju, but Chang-il saves her. When Dr. Go comes back to his mind, everything turns out to be his dream.