On the streets of Tokyo, multiple murders have occurred day and night by terrifying beings created one hundred years ago by humans, called Therions;
They were the evolution of science and man, created with human and animal DNA these humanoid beings had similarities with humans, possessed own their own mind, were considered perfect, but there was a genetic mistake and it got out of control. Therions started to created their own independent race and consume human flesh to survive due to their animal DNA, from that day on the humans and the Therions were enemies.
Daiki Mitsumoto, a seventeen years old young student, concerned about the living conditions in the world. One day his life changes, walking down an alley; a strange dog appears, approaches him wildly and bites on his shoulder and leaves him badly wounded, survives without knowing that bite will change everything. Since then, Daiki’s life changes completely to become the Pantherion, the Dark Beast.