Juurokusai no Akuma

A daghter of the Kaido family had died within a week of her 16th birthday. Masumi Kaido, 16 years old, asks her best friend, Emi Tsuki, to stay at her home until a week has passed. Masumi and Emi have become friends with each other rapidly since entering high school and discover that their birthdays are the same. And Emi begins to see ghosts after her birthday. In Masumi's house, a girl in a white kimono with a black cat appears in front of Emi and kills Emi. What exactly is the curse that attacks the Kaido family?