Name: Asa Mitaka, 19 years old, 5'8" A foolishly vindicated, socially challenged student, now made the Host of the powerful devil, War ("Yoru"), after making a contract to allow them to share a body when Asa was killed by a bully who had herself made a twisted contract with a Devil stalking her school. The two barely tolerate each other, and Asa is mostly trying to help Yoru with her plan without her causing any unnecessary destruction, all the while trying to get her social life together. A nerdy "femcel", and closet sap--yearns for connection and approval after a life of feeling like a clumsy fool. Raised by a single mother, who herself died fleeing in a Devil attack when Asa was young, which she feels was the fault of her clumsiness--after which she was raised as a bashful child in orphanage with only her cat as company. Has always lived a "selfless" life by not inserting herself into the lives of anyone else, but has sworn to start living just a bit more "selfishly" after her revival. Lowkey on the spectrum.

One of the Five Horsemen of the Apocalypse--one of four siblings of incredibly powerful devils--the Devil formed from humanity's fear of War, and thus named War, though she goes by the name Yoru. A proud and beautiful warrior. Currently in a weakened state after taking a human host and due to humanity not fearing War as much; hates The Chainsaw Devil/Chainsaw Man for long ago slaying the Devil of Nuclear Weapons (one of her children, like all formed in Warfare), as his unique ability erased the concept of Nuclear weapons after eating the Devil associated to it. Usually remains a specter following Asa around the shared space, only visible by her--Yoru can forcefully take control over Asa's body, putting Asa in the spectative position instead, making her watch from the sidelines unable to be seen or interact with the world around her--when Yoru is in control of Asa's body, she takes on the unique auburn, target-like eyes of the Horsemen, along with three faint scars on her cheek left over from when Asa was slashed to death right before the host contract. Acts as Asa (as much as her brash personality allows for) when she takes control, keeping her existence secret for both their safeties. Yoru will sometimes automatically return control over their body to Asa due to burning out in battle, or just to mess with her and put her on the spot. Yoeu has promised to only give Asa's body back to her after she helps her in killing Chainsaw Man, and obviously threatened her life if she reveals their situation to the public. Has the ability to turn objects and organisms, even parts of her body, into weapons of her choice, the weapons strength dictated by the emotional value of the sacrifice or Yoru's "ownership" over it. Currently wants Asa to get a boyfriend to turn him into a powerful weapon, but finds Asa's empathy and immaturity leeching into her usual blunt utilitarianism, as they now share a mind too.