After my korean/japanese horror movie marathon I've realized there are several South Korean "horror" movies with sometimes subtle, sometimes obvious lesbian undertones. Some scenes and dialogues can be explained by best friend situations others have it written all over them with capital bold letters.

"whispering corridors" series in 1998.
all 4 movies of the series are set in girl's school.

1. Whispering Corridors (Original Title: Yeogo goedam, 1998)

Set in an all-girls high school, the movie depicts the life of high school students in South Korea, dealing with bullies, abusive teachers and pressure to get good grades. The horror starts when teacher and students commit suicide and somehow the new teacher and two students are involved.
In the end it turns out that everything happened because of lost "friendship".

2. Memento Mori, 1999


Two of the main characters are actually a couple in this movie and the other students are talking behind their backs. Then one of them jumps off the school's roof. Another girl finds her diary and through flashbacks we're told what happened.

there's already a thread: Memento Mori

3. Wishing Stairs, 2003


This one is set in a ballet school. Again the 2 main characters (played by Song Ji Hyo and Park Han Byul) are best friends at the beginning but a competition brings out the worst in one of them, resulting in the death of the other. Brought back by the "wishing stairs" the ghost of the dead girl returns to haunt the school.
Although it's not explicit as "memento mori" it's pretty obvious that the dead girl was in love with her best friend stating "all i want is you".

4. Voice aka Voice Letter, 2005

A student (Kim Ok Bin) who practices singing alone in school is mysteriously murdered but her ghost is still here. The next day only her best friend (Seo Ji Hye) notices that something is wrong. She discovers that she an hear her dead friend's voice. Together they try to solve the mystery but the story turns out complicated, involving a rumored lesbian teacher and a former student who committed suicide.



Nightmare (Original Title: Gawi, 2000)


Six friends of Hye-Jin are being killed one by one. Is this the work of the vengeful spirit of a girl who committed suicide because of them?
This movie has an interesting story though the "special effects" are sometimes just comical.
Kim Guy Ri who plays Hye-Jin also starred in Whispering Corridors. this was the first movie for Ha Ji Won.