The Dream Devil is a devil which appears in humans’ dreams. If the Dream Devil appears， it’s be said that the occurrence of the dream will become true， and it comes out and the person will die on the 7th day―there is a rumor like that. A girl， Atsuko Maehara(means a warmhearted child on a fore field) is fascinated by the Dream Devil， and days that she cannot sleep every night continues… One day Astuko talks with her best friend， Tomoka Kasahara (means a wisdom shade on a fragrant place) over the dreams， but various strange phenomena happen from the night. The Dream Devil comes out into her dreams and unnatural phenomena happen one after another!? Of course， adults (police) don’t believe such a talk. However， among these adults， only a detective， Maiko Osawa (means a hemp cloth from a big stream) thinks that the contents what they’re mentioning resemble her real sister’s death cause， and decides to investigate the incident… Well， is it possible for them to escape from the death due to the time limit for seven days?