Ajin: Demi-Human Ajin (Japanese Language) Kaito is Kei's childhood friend and the only human person in the entire country who makes an effort to help Kei despite the fact he is an Ajin. He retains a very positive, determined attitude. He is also very resourceful and though he is not as intelligent as Kei, he is able to make tactical decisions while they were on the run together. He is a young man of average build. His eyes are the same golden color of his hair beneath thick, heavy eyebrows..