Rui was born with an extremely fragile body that made it too risky to be outside too long or to move too much. He has ocean-blue eyes, brown, shoulder-length hair that seems to curl around his face, and very fair skin. He wants to and is willing to make friends with the other young kids in his village, but it’s too dangerous to go outside and play, because of how fragile he is. Rui Ike’s hearing about the Demon Slayers who help save people’s lives, and genuinely looks up to them.