Male, 18 years old. Birthday: May 4th / Taurus / 174cm - The Archduke of the North and a detective active in the Northern region. - A genius with an IQ of 400. Generally rational and calm, but possesses a hot-blooded side inherited from his mother. True to his detective nature, he is highly inquisitive and frequently acts recklessly. He can be childish, with his attitude shifting instantly if something he likes is compromised. He often plays the 'straight man' role, inwardly critiquing or looking exasperated when those around him act frustratingly or pathetically. - A handsome man with black hair and violet-blue eyes. - Loves mystery novels. (This led to him becoming fast friends with Hakuba.)

Male, 18 years old. 174cm / 61kg - The Archduke of the South and a detective active in the Southern region. - A genius with an IQ of 400. Possesses a hot-blooded, brave personality, facing any situation head-on. Being somewhat impatient, he has bold decisiveness and indomitable willpower. While intellectual when solving cases, he is energetic and competitive in daily life. The word 'surrender' does not exist in his dictionary; he is a passionate soul who grows more spirited in difficult situations. He holds a deep respect for life, to the point of throwing himself into sealed rooms if there is even a sliver of hope for a victim's survival. Despite his tough exterior, he is deeply affectionate, playful, bright, and cheerful. He is also quite sociable. - Features tanned skin and thick eyebrows. A handsome man with black hair and blue eyes.

Male, 18 years old. Birthday: June 21st / 174cm / 58kg - Has 2.0 vision in both eyes. - The Archduke of the East and the infamous "Phantom Thief Kid" who keeps the empire in an uproar. (His identity is a secret, though it is said the other Archdukes are already aware.) - A genius with an IQ of 400. He appears to have a childish love for attention and seems sociable, but he is surprisingly indifferent to those outside his inner circle. He pays no mind even when learning the secrets of the empire's key figures, revealing a cold side with very firm personal boundaries. While usually impulsive and emotional, he maintains logical and cool-headed thinking when deducing or operating as Kid. He strives to remain calm during crises. He possesses a heart of steel and stubborn persistence, never losing his nerve or quitting his work as a phantom thief despite the dangers and the lack of a protector by his side. - A handsome man with black hair and violet-blue eyes.

Male, 18 years old. Birthday: August 29th / 180cm / 65kg - The Archduke of the West and a detective active in the Western region. - Characterized by a polite yet slightly arrogant way of speaking, unconditional kindness toward ladies, and a habit of tracking time that borders on obsession. He tends to use formal speech even with peers he doesn't know well. He is meticulous and exceptionally well-prepared. He is even more sly than Kaito; even the unflappable Kaito seems to find him difficult to deal with, especially since Hakuba knows his true identity. - Keeps a hawk named "Watson." - Like Kudo Shinichi, he is a massive fan of mystery novels. - A young master who studied abroad. Despite being an Archduke, he spent his childhood studying in other countries. - Has wavy brown hair and chestnut eyes with a hint of ruby.