One day, during a mission with a 0% danger probability, an A-class adventurer Kaitos comes across a mysterious witch and accidentally disrupts her ritual. As a result, many evil spirits called Binds are released into the world and Kaitos, being affected by the ritual too, doesn't have much choice but to start helping the witch in sealing the Binds that have been set free. Enlisting the support from his friends both new and old, our hero sets out on a quest which ends up being much more complicated than a simple Bind hunt...