Ogre Slayer is about a young man who hunts ogres. The young man was born of an ogre's corpse, like the oni born of human's body, making him pure ogre blood. Though he was born like an ogre, he has the appearance of a human. Instead of being born with horns like traditional Japanese ogres, he was born with a sword. The young man doesn't have a name, but his sword is called Onikirimaru, the Ogre Slayer.