Prologue

What's the world like if you get to know all of its secrets? What does it feel like when you find out about who you truly are? And what does it feel like to suddenly be a stranger in the world you thought you knew?
Yuki and Hiko, both orphans, are over the death of their parents now, trying to move on as usual. But suddenly, a gate to another world opens to them as they find themselves as half human and half demon one day. As that happens, they get to know the Hell Demons lead by the devil Lucifer and his brother Satan and find close friends among them, but they also learn about suffering and fear. The world as they used to know it... is not what it seems like...