Kio Kaidou (海堂 貴緒)
Background
Despite his early presence as a character who exists solely to create a lighter atmosphere among a very dark story, he gradually gains depth and justifies his existence as the story progresses. He becomes a loud voice that champions pacifism and self-worth. This contrasts strongly against Soubi's submissive nature that willingly accepts violent treatment and strongly desires to be completely controlled, albeit from only very certain people. More significantly, Kio's views are shared by Ritsuka. Together, they provide a very black-and-white atmosphere that allows only one line of thinking.