High school student Yumeji Fujiwara possesses the ability to perceive people's dreams. Although these visions are never clear or concrete, he can predict them by sensing a person's "aura." Typically, this talent serves as an amusing trick for his classmates, yet Yumeji only ever sees himself trapped in the same recurring nightmare every night. Surprisingly, the nightmare persists during the day, even before Yumeji has fallen asleep. This unexpected occurrence was triggered by a dream demon—an inhabitant of the dream world who intends to use Yumeji's body as a vessel to fully enter the real world. However, Yumeji is rescued by the timely arrival of Merry Nightmare, another dream demon who can somehow manifest physically without a host and is instead attempting to return to her own realm. As more dream demons continue to breach reality, it falls to Yumeji and Merry to fight back against the invasion before everyone's nightmares become materialized.