"I-I'm sorry... I'll protect you from now on. I promise."
Her eyes closed tightly; the short haired girl with black hair breathed heavily, on the ground on her hands as if trying to stop herself from something. Sweat beaded down her forehead, and steam appeared to rise from her burning body into the cool air. She appeared human, but when she opened her eyes just a little, displaying her pain and agony from self control, the red hidden behind her pupils gave away what she really was.
"Yurina." A long haired girl dressed in a modern onmyouji practitioner's outfit, something more like a white military dress than a priestess's clothes, spoke to the struggling youkai.
The black haired girl, Yurina, glared at the long haired girl, the descendant of the famous Abe no Seimei and heir to the Nagahama family of onmyouji, Nagahama Neru. The youkai girl wanted to scream, but her throat was burning, so parched and thirsty. She tried pushing herself to stand up but instead fell to the ground.
Yurina glared at Neru, at that red blood leaking down the human's wrist, dripping on the ground, at the wound that the onmyouji had so callously cut with a ceremonial knife.
Yet, the youkai girl was thirsty, burning and raging, her body telling her that she wanted to consume the rich blood of the onmyouji. She held herself back, not wanting to fall into acting like such an animal to her subjugator. Her vision flickered.
The next thing Yurina knew, Neru crouched in front of her. Neru extended her wrist, letting the smell of blood enter Yurina's nose. "Drink." The long haired girl practically forced the red liquid down the short haired girl's throat.
Once the blood touched her tongue, Yurina could no longer stop. Taken over by her desires, her mouth clamped onto Neru's wrist and hand. The youkai's hands clung onto Neru as if the onmyouji would run away. Eating ravenously, her fangs, which had appeared despite her human form, dug into Neru's flesh. With her saliva healing the human wound, she took to licking up and down Neru's wrist, biting into the onmyouji's hand, hearing the crack of fingers but not paying attention at all, lost in a haze of hunger.
"Stop." Neru commanded.
Grabbing Yurina's head with her good hand, Neru briefly materialized the chains of the contract between shikigami and onmyouji to throw the youkai away. Yurina's pupils pulsated, burning red before settling back to mostly black, as she slowly regained control of herself while held down.
Yurina wiped away the blood on her mouth quickly.
"You're truly a fool." Neru said quietly, "Scion of the White Tiger, Hirate Yurina." She wore an expression that Yurina hated to see.
Yurina frowned, "I don't need your blood." Her hatred for the human who bound her with contract clashed with her guilt for tearing apart Neru's hand. She had forgotten how long ago they had started this cycle of refusal and forcing the consumption of blood.
Neru looked at Yurina seemingly calmly, but her eyes betrayed a mocking smile.
Naturally, youkai would have to eat somehow, and it was the truth that human flesh was a common youkai food because what the youkai needed was spiritual sustenance. With the advances of human technology, it became harder and harder to get by through the energy of nature. Living beings had to be consumed, and well enough, humans were some of the richest ones.
Perhaps the practice of onmyouji had started in a peaceful partnership between the supernatural non-humans and the humans, but at some point in time, it had devolved into mostly a master-servant relationship. The youkai were at war with the humans.