Welcome to the world of Yuonov, an Earth clone that humans created thousands of years ago. Animals soon evolved to human technology and took over the world, replacing the humans of Yuonov and learning to live in harmony from eating only plants. Not everything in Yuonov is peaceful, though. Join Tan and her friends as they try to survive in a world with angels, demons, anti-angels, and anti-demons caught in an eternal war. As Forest Nymphs live within every crook and cranny of forest trees and the Mages keep themselves secret to protect Yuonov, Tan is but a mortal trying to make it through the world. Tan's life isn't completely normal, though. She has a curse; she can't die. No matter how much she wants to die, she must stay alive, only spawning a demon and reviving each time she dies. Detective, Tan's best friend since grade school, is dealing with deep, emotional issues. When he was young, somebody killed his parents. This made him a detective, and his new goal in life is to find the culprit of his parents' murder. Watch as Tan, Detective, and other characters go through their lives and develop in the weird, paranormal and complicated world of Yuonov. Watch them become strong. Watch them become fighters. Watch them become The Mercenaries.