Yumeji Fujiwara, a high school student, possesses the unique ability to glimpse into people's dreams through their auras. Despite the dream images being hazy, Yumeji can predict them accurately. However, he himself is haunted by a recurring nightmare, which starts intruding into his waking hours. This anomaly is caused by a malevolent dream demon seeking to exploit Yumeji's body to enter the real world. Fortunately, Merry Nightmare, a dream demon who materializes independently, intervenes to save Yumeji. Merry aims to find a way back to her dream realm. As more dream demons attempt to cross over, Yumeji and Merry must unite to prevent the invasion and stop the terrifying manifestation of everyone's worst nightmares.