Whispering Corridors (1998; dir. Park Ki-hyung) 1
I think this girls’ high school B-horror trilogy (along with Memento Mori and Wishing Stairs) is generally over-rated by critics. These are all based around the “ghost that must be appeased” plot; this one in particular has some glaring inconsistencies in the storyline.
Memento Mori (1999; dir. Kim Tae-yong, Min Kyu-dong) 3
I felt that this was the best of the three, though it's probably more drama than horror. Take or leave the haunted diary, but I thought the large-scale ending was fun.
Wishing Stairs (2003; dir. Yun Jae-yon) 2
There were a couple of good ideas sprinkled throughout this tale of high school rivalries, but mostly this is a mediocre B-horror film with fat-suits and blood raining from bathroom plumbing.