Being both human and demon is not an easy task. Especially when you're not excepted by one and have to hide your true self from the next. Anima Matoi is your typical Japanese girl but with a twist. She was born as a human but was bitten by a demon, but she only turned half demon. Because of her inability to control her emotions and form, the demons took her under their wing, seeing her as an asset to war. She was the first successful human to be bitten by a demon and live which the demons thought would be a great advantage. However, she didn't quite live up to their standards so they banished her from theirs lands. Anima lived by herself for 7 years, training herself, sometimes stumbling into unwanted battles but eventually she sought it as her training. After having nothing else to learn, she decided it was time for her to be among the humans who is half her kind. To her it was a big advantage on knowing how both species fight when it came to war. Izumi, a boy not so skilled happened to have the privilege of being admired by Anima which is was almost impossible, and she took it upon herself to train him. For Anima, for the first time in all her life, she felt like if she belonged even though she had to hide her true self. But at the ball for humans, it was mating season for demons and Anima sensed one among the humans. But not being full demon she couldn't tell exactly where it was but she knew that it knew where she was. It finally revealed itself making Anima have no choice but to reveal herself as well and fight it to the death. How will Anima's new "family" react to knowing that the new recruit in their kind was half demon, half human? Will they except her once again as a member? Or will they banish her from their kind forcing her to roam the world alone once again?