Ryuta and his friends from the science club visit a museum exhibit on Thomas Edison and it's there they learn about one of his proposed inventions called the "spirit phone" which would enable communication with the deceased. Later that day they bump into a shaman who claims she has a message from Edison. In an instant Ryuta is given the necessary knowledge he needs to construct the device and decides to go for it, so beginning a spiritual adventure.

(Source: Anime News Network)