Our heroine, Cocoro, woke up in a mysterious town not knowing anything about herself. An owl approached her and invited her to a school. Once they arrived there, he explained that the world they were in is called the Netherworld. It is a place between heaven and hell where souls with deep regrets in their past life gathers. The school is where souls take lessons in order to become a shinigami. The owl is the principal of the school. He invited her to enroll there and she accepted.
Fast forward after she enrolled, the pair up exam was coming up. Although Cocoro studied a lot for it (or at least she said so), she miraculously scored two points in every subject and was placed into the special supplemetary class. There she met Kairi, Yoru, Ame and Syun (her classmates), along with Nami (her homeroom teacher) and Yuyu (Nami’s familiar).