The king of the beasts and demons receives female human sacrifices to assert the dominance over the human race. However, the 99th sacrifice intrigues him and lets her stay as his consort.

Located at the end of the world, the Kingdom of Ozmargo is inhabited by beasts of all shapes and forms, ruled by a fearsome nameless king. After a hundred-year war between Ozmargo and the neighboring human kingdom ended, a peace treaty was signed: every year, a sacrifice must be sent to be devoured by the king on the night of revelation. Sariphi is the 99th and latest human sacrifice. Although frail-looking, she neither fears the king nor has a family or home to return to should she manage to escape from her impending demise. Intrigued by the audacious girl, the king lets Sariphi roam around the palace despite the disapproval of his advisor, Anubis. Little by little, the king and Sariphi begin to warm up to each other, but the night of revelation is fast approaching. Unbeknownst to them, the fateful day unleashes a series of events that will change the course of destiny of not only Sariphi and the king but also of their respective worlds.—MAL Rewrite

One hundred years ago, a grave tradition was born in a land where demons live among people: a human must be sacrificed to the King of Beasts. But when Sariphi, the 99th sacrifice, is offered to the King, she isn't afraid at all. Intrigued by her calm and cute nature, the King decides to spare her life with plans to make her his bride.—Crunchyroll