The fourth prince of the Kou Empire. A young man characterized by burn scars covering half of his face and body, long hair tied up, split eyebrows shared by his siblings, and a mole near his mouth. He bears a striking resemblance to his father, Hakutoku, and his brothers, Hakuyu and Hakuren. He has heterochromia, with a blue right eye and a grey left eye. Along with his sister, he is established as one of the most strikingly beautiful characters in the series, a fact he is quietly aware of. He harbors a deep hatred for his mother, Gyokuen, who killed his brothers. He lost his left arm due to Isnan's magic after conquering Zagan (in the anime, it was severed by Isaac). His personality is serious and polite, and he treats people and matters with sincerity. He cannot overlook things that defy reason and strives to uphold what he believes is right, possessing a "painfully straightforward Rukh." While he usually acts calm and stout-hearted, this is an intentional imitation of his late brother's demeanor; in reality, he is kind-hearted and a bit of a crybaby. He generally speaks politely. First person: I (casual/masculine). He addresses others by adding "-dono" to their names. He only speaks bluntly to Judar.

One of the four "Magi" in the world. Known as the "Black Sun." He has fallen into depravity and manipulates Black Rukh. A young man characterized by red eyes, long black hair in a thick braid, and Middle Eastern-style attire. He is a picky eater and has slightly paler skin than other characters his age. He is selfish, short-tempered, and proud. He is insolent toward everyone and speaks without filtering his words. He is highly bellicose and loves war, to the point that his past dream for the future was "World Conquest," and in the final volume, he aimed for "Interdimensional Conquest." However, outside of combat, he is listless and lazy, often complaining that "every day is boring." Despite holding a priestly office, he doesn't seem to do any actual work, instead spending his time eating peaches and napping around the castle. He eventually selects Hakuryu as his King, and during the Kou Empire arc, he shows a surprisingly devoted side, energetically supporting Hakuryu with magic and calling him "My King." He has an extreme temperament: he is enthusiastic about things he likes or finds interesting, but completely useless at things he dislikes or finds boring. He often dumps the latter onto Hakuryu, saying, "Hakuryu will do it." He has a foul mouth. First person: I (rough/masculine). He generally addresses people by their names without honorifics. He has a somewhat childish, honest side.