Tsukasa is a yokai who got injured badly by a evil spirit….a human named Emu Otori patched up his injuries despite knowing he is a Yokai!? “How is she not scared?” Tsukasa thinks

Tsukasa notices that this strange girl has a lot of power in her body…this powerless Yokai wants to be strong enough to fight evil spirits….to gain that power he has to… make Emu his master and her powers will be Tsukasa’s. (Basically a yokai and human make a contract where the yokai takes the power the human has but they have to obey them) When a human and a yokai makes a contract. The Yokai follows their masters commands Tsukasa: “Miss. Will you be my master please? I PROMISE TOGETHER WE WILL BE A UNSTOPPABLE DUO!! HAHAHAHA!!!”