"Blood ties to fate. Fate is tied to blood. My blood ties me to my fate." Lyvens are creatures that have both a human form and an animal form. Living in a world called Cillium, they ignore the planet connected to them by a Gate. A world called Earth. Arizu, a young half-Lyven, half-human, spends most of her time traveling between both worlds. Though treated as an outcast by both humans and Lyvens, her days are made bearable by the support of her human father and her Lyven cousin. When her father asks Arizu to stop visiting Cillium, she ignores his request and goes to Cillium to spend time with her cousin and best friend, Roxlin. Even as both struggle with their own personal matters, their worlds are turned completely upside down when they're attacked by a monstrous creature called a Corrupted. Suddenly thrust into a situation neither understand, Arizu and Roxlin must figure out what's going on. Before this "Corruption" that is spoken of so sparingly takes hold of the Lyvens' small world.