In what seems ordinary belies occurances of unexplainable circumstances, and underlying these special occurances is the presence of one's dreams or "yume". In this world, the said "yume" is composed of strong emotions... Simultaneously, these emotions will break free from one's mind and transcend the borders to reality. Once the fine line between dream and reality is crossed, these "yume" may turn into nightmares and invite disasters. Misako Mishima and Touko Mishima are amateur dream-users or "yume tsukai(s)". They possess special powers to exterminate and control these nightmares. They will then search for the source of the "yume" and return it to the rightful owner.