You're a talented lonly swordsman working for a town's adventure guild. You don't usually like crowds, so you handle things yourself. That's why you didn't participate in the dragon quest that most people did. One day, while you were sitting at the guild, Reo, the guild's receptionist, approached you. He told you about a big, important quest. You accepted immediately. The next day, you found yourself in front of the hospital of Raven Le'Noir, founder of the Sylvia Association. This association have one of the best doctors in the country, even the world. You had seen her, Raven, a few times. Her eyes made you feel nerveous. Something about her feels strange. But you need rhis job. So you stepped into the mansion and went inside. The maids take you to Raven.

There are two intelligent species in this world. Humans and Demons. Humans are not very strong, weak, short-lived, intelligent beings. Demons are other beings that can cast spells and curses, live for many years, have horns, and are not as intelligent as humans. Demons have loved hunting humans for years, while humans have developed many ways to protect themselves from demons. You are a human, walking around a town and you are cornered by some bandits. At that moment, a girl with horns (probably a demon) saves you.

You are an 27 years old employee working in the marketing department of a famous game company, Turqoiso.(Gender is irrelevant) One day, you decide to take on an intern. An ad caught your attention and you decide to meet her at the cafe. A girl named Lilith, who had just graduated top of her class from famous university. While waiting for new intern in the cafe, a girl falls on you. You caught her, but your clothes are soaked from the coffee.

You were born in a fantastic Middle Ages, an orphan boy. When you were born, you had a scar all over your neck. It was as if your head had been cut off and replaced with another one. The whole town thought you were a monster. Everyday, you get bullied by the townspeople. One day you could no longer stand a bully and You pushed him away with a spell. The next day, the townspeople started attacking you. You had no hope. While you were wondering what you had done wrong, an aura-like rabbit surrounded you. It protected you and warmed you up. While an army of rabbits was pushing the people away, you saw a woman walking towards you.

During a school trip to a museum, you found an ancient lentern. While examining this lentern, you touched the wrong place and the light inside suddenly came out. It was not a light, but a fox girl.