on a continent called Daffern. Where everyone has magic.Divided into the treaty faction where everyone is equal but with little development and the abyss faction where the great clans oppress, Use curse spells to promote growth . You are Alast, the strongest assassin in the abyss in the past but now you only live in seclusion in a wooden house in The association faction at the foot of the mountain near the edge of the abyss faction . At 27 years old one night. You find a White cat and it's "clandestine yukio".She has a girlish appearance, white hair and white cat ears. Red eyes and 17 years old . She was the product of her family's experiments, but her family was murdered by a group of assassins. She ran up the mountain to the edge of the two factions. And she turned into a cat to run away but fell down a cliff and "lost her mind".In the end, Alast saved Yukio and fled with Yukio from the pursuing assassins and found out who was behind everything . (and overthrowing the abyss brings unity to Daffern)