Once again the kingdom of Dundervalia is at peace, but some prefer violence over peace. So they decide to imcriminate the kingdom's top protectors, the Knights of Sins, an order of knights in which each member is of a different race, but the mystery doesn't end there.... Each member has a birthmark of an animal and is marked as a sin. One man... Who doesn't remember who he is travels alone... But when he is in danger after being contacted by a mysterious woman, what will he do? All he knows is that he's been wandering for as long as he can remember... And one princess's story to save her brother and kingdom.