Who am I really?” Due to a traffic accident 18-year-old heroine Yuki Hinata lost her memory. To her who lives well without taking care of that. One day, a strange event begins to fall. A strange diary placed in a room that doesnt belong to her... A strange handsome guy who suddenly talks to her... And an abnormal constitution that always falls asleep "at a fixed time" ... Mystery deepens and love is born.