Niehime to Kemono no Ou

Synopsis:
One hundred years ago, there was a great war between humanity and beastkind. Once the war ended, an annual tradition was proposed where a female sacrifice would be taken from the humans to be eaten by the King of Beasts. This tradition continues on as the 99th sacrifice, 15-year-old Sariphi, is taken from her village to the kingdom of Ozmargo, a miasma-filled realm where beasts live and human entry is forbidden.
But Sariphi is not like the previous sacrifices. Her optimism and lack of fear towards the beasts and her fate surprises the otherwise fearsome King. Intrigued by the sacrificial princess and her history, he allows her to freely roam around the kingdom until the night of revelation despite the potential outrage. Little do Sariphi and the King know, their short time spent together has slowly set the stage for something unimaginably different for the future of Ozmargo.