Under the onslaught of demons, Tokyo was sealed. Every day, the demons lurk in the shadows and when the sun set, they come out of their hidings to prey off humans. To ensure their survival, a group of youngsters contracted with demons, gained their power to fight off the forces against them.
In this dangerous game of survival, if they don't win by the end of the seventh day, the world and themselves would be swallowed by darkness. Utilize the power of your demons and save your skin. The fate of the world rests in your hands, taste the danger and seek to make the right choices.