***a Rin x OC story*** [[sexual content in later chapters just warning you]] Ares "Air" Yagami is the daughter of Lucifer. I know what you're thinking, cool Rin has a sister now right? Wrong. 16 years ago its been discovered by a compact group of exorcists that Lucifer and Satan are two completely different demons after one of their members was overtaken by Lucifer and burst into white flames. Word got around and now everyone knows of Lucifer's existence. Air, born a year after that, now 15 years old has come across Rin Okumura and they are both determined to face and defeat their own fathers for their own reasons. We follow Air through her journey as she meets new people and finds out more about her past and her mother, all the while she is confused about a possible love interest developing from her and Rin's strange and deluded friendship. At a point she must choose; sacrifice her life for the sake of killing Lucifer and having one last happy memory, ... or keep on living life where she can stay with her friends and loved ones but to continue to remain ignorant of the answers to her most important questions.

It had been almost two years after Satan takes over Yukio Okumura, and he soon finds out that he will be working alongside his ex-girlfriend. They get back together, and Tuno realizes how much he has changed in the past two years. Will they beat their worst enemies and come closer?

Tuno and Yukio have started a new life together with their twin boys. Will it really be a happy ending for these two?