Eden Schmidt is on a boat heading to Cantica, the most fearsome Demon prison in all of the land. She is attached with her friend, Adanna, and the Demon soldier, Aaron, two of the five souls that she has to find in order to save Zemiothstai, the world of purgatory, from the clutches of Satan. Until she brings all five souls together, she cannot hope to unlock the gates of heaven.

As she travels on a boat that brings her to Cantica, she believes that things cannot be much worse. Aaron has already informed her that the evil soul, Donovan, that is Satan's right-hand man has seen to it that one of his most powerful generals, General Yuri, will guard her personally. She has also heard that the Demon prison is so tight that nobody will be able to escape. But she has to. She has made a promise to Adanna's sister, Thema, that they would meet again.