Diary (also known as Mon seung) is a 2006 Chinese thriller film directed by Oxide Pang.

Winnie Leung (Charlene Choi), a dour loner of a young woman, spends her days in her apartment, cooking meals, carving wooden dolls and waiting for her boyfriend, Seth Lau (Shawn Yue) to come home.

She then ventures outside and sees a man named Ray (also Shawn Yue), and invites him back to her apartment for a meal.

She left feeling cheated, only to come back to the same vendor and later on realizing she already has bought fish.

The reality she knows started to fade and melt in with what is currently happening, revealing the instances on how she have lured Ray and detaining him.

Eventually, Winnie's instability made her kill Ray assuming that he's having an affair with a lady voice over the phone.