White Christmas
화이트 크리스마스 (original)
Kim Yo Han is a psychiatrist who gets involved in a serial murder when his car broke down on Christmas Eve during a sudden storm and he is forced to take shelter at a private high school. Seven students and a teacher are also there over the winter break, but they are gradually murdered one by one as they receive letters from a killer who wants revenge for the death of his mother and sister.
Starring Kim Sang-kyung, Baek Sung-hyun, Kim Young-kwang, Lee Soo-hyuk, Kwak Jung-wook, Hong Jong-hyun, Esom, Kim Woo-bin, Sung Joon, Jung Suk-won
It's a mystery and crime show, and has a rating of 8 out of 10 from Imdb which is usually fine for this kind of show.
Watch it here
Not found streaming from Switzerland.