Characterized by black hair with red streaks, he always wears an eyepatch over his right eye. He claims to be sealing "Forbidden Dark Magic" within that eye. He refers to himself as "Valhazak, the Dark Dragon Knight," and behaves with a grand, valiant, and aggressive persona to match. His real name is Ryuya Koidzumi. He is 16 years old and a high school freshman. His true personality is bright, energetic, and innocent. He is kind to everyone and well-liked. Whenever there is an opening, his chuunibyou tendencies flare up. However, he finds it incredibly embarrassing to have his chuunibyou antics seen by family—especially by Guest, whom he respects. If caught, he panics and tries desperately to hide it.