Ao
Was most probably born when Satomi Rio saved Sousuke’s life five years ago, but at the cost of splitting his soul in half.
Ao also holds their childhood memories, which is the reason why the other Sousuke can’t remember much.
Ao seems obsessed with Shino, he likes teasing Shino but maybe that is only a facade to hide his loneliness, because Shino chose to be with his other half, Sousuke.
Ao’s body parts are incomplete, since the other Sousuke took most of them, so he has gone on a hunt to collect the body parts he’s missing. He obtained his heart from Keno, and his left eye from a woman named Kohaku. He specially picked Kohaku’s eye because Shino once praised Kohaku for her beautiful golden eyes.
Sousuke’s bead ultimately chooses Ao as its owner, which causes Sousuke to slowly die.