The Incredible Truth.

An artist named Jiajia promised to show her girl friend Wei Ling around in Japan but eventually fails to show up for no reason. After Wei Ling goes and gets accommodated in a family-run hot spring hotel of Shimizu, Jiajia's Japanese boyfriend, she begins her endless weird experience as if she's haunted, and the hotel even sinks into a series of horrible homicides, in which the victims are all family members of the Shimizu's without exception. Every clue found is connected to Jiajia.