Oni (鬼おに) are a humanoid species with a unique type of blood which they can manipulate in various ways. This ability may remain dormant for most of an Oni's life, causing many of them to be unaware of their lineage as a result. When an Oni's abilities do finally manifest, usually shown by a pair of ethereal horns which sprouts from the top of their head, it's referred to as an "awakening". The Oni are engaged in an ongoing conflict with the Momotaro, who seek to oppress and eventually eradicate them. The Oni Corporation is an organization which exists in response to this threat and serves to provide assistance and protection to all Onis.