What would you do when you have to attend a costume party you really didn’t want to? In the case of our protagonist, you find the cheapest thing you can buy and find a way to justify it as a costume to anyone who asks. But what happens when that innocent party leads to an event that completely changes your life?

An event that not only teleports our protagonist to the ancient past of a familiar world but also changes his species and gender. And while our hero knows what’ll happen eventually, even she can’t know if her existence will invalidate the history she knows must happen.

But can a young demon survive in a world so predisposed to light magic? Or will all her efforts fail as she destroys fate while becoming the very villain she appears to be?