On the eve of destruction, four demons awaken....

There was once a time where demons and Grim Reapers lived with humans. They kept their identity a secret from most and tried to keep balance between their two worlds. Everything was going well and both sides were able to live in peace. Hiding from the human world was Tartarus Sanctum, a place where Apprentices to the Grim Reaper could live and learn their craft of reaping souls. In addition, four Apprentices were chosen to keep balance in the Upper World and the Underworld. This year, the responsibility had fallen on four young demons: Yuka, Tessa, Kaska, and Avani. They were known as Guardians of the Underworld and were expected to follow through with their responsibilities.

But the girls were not ready to take on big responsibilities or prepare themselves for the future. At the moment, all they want to have as normal of a life as possible. Not everyone else felt that way so they chose to run from Tartarus Sanctum. It was when they ran away that the whole world came apart. In one night, the other Apprentices were murdered and their home was destroyed. Now demons and humans are against each other. There is a war on the rise. Both worlds are collapsing and hope lies with the new Guardians. They are awake. They are ready. But they have a long way to go before they can save the world.