The story revolves around Tatsumi Hōjyō, a seventeen-year-old girl and heir to a clan of Yumegari (dream hunters). The dream hunter's mission is to investigate the dreams of others and actively participate in them if necessary. A yumegari is bound by fate to a yumemori, one who watches the dreams of a Yumegari and prevents them from falling into an eternal sleep.
When Tatsumi's mother and father, the preceding yumegari and yumemori, die in the execution of their duties, Tatsumi inherits the job. She then sets off for Tokyo to find her yumemori, twenty-eight-year-old Kyousuke Kaga. Tatsumi takes up residence with Kyousuke so they can get a better understand of each other. Despite the warnings from her clan about Kyousuke, Tatsumi continues to work with him, fulfilling her dangerous and uncertain role as a yumegari.