Yuya Nomoto, an ordinary college student, met a mysterious high-school student called Hitomi after being involved in an incident, and saw her transform into a beast and fight a Leo monster at a landfill. They're Therianthropes who have brains of humans and fangs of beasts. Hitomi is Ratel, a Brute with the strongest killer instinct. Nomoto gets involved in their battles called Killing Bites.
