Grévil de Blois (グレヴィール・ド・ブロワ, Gurevīru do Burowa) is an aristocrat who works as an inspector in Sauville's police department. He can be easily distinguished for his drill-like hairstyle, and is usually seen visiting Victorique de Blois to consult for cases he handle.
Grévil is a tall and handsome man in his 20s. He fashions a weird drill-like hairstyle which requires a long time to set, and is rarely seen with his hair unstyled. In the past, however, Grevil is often seen with his shoulder-length hair left unkempt. According to Kazuya Kujō, Grevil's hair is silky at first look, and Cecile Lafitte describes his hair as having the scent of flowers, which Grevil blames on the fragrant shampoo he uses.
He is also usually seen wearing a white coat and slacks, and wears a pink ascot. In the past, he would instead resort to a blue ascot with his coat.
In the past, Grevil displays a more mild-mannered behavior, soft-spoken and always calm. However, he now acts in a more eccentric way, sometimes exaggerating his actions and manner of speaking in front of familiar people. Despite his comical behaviour, he does show a more serious side when obediently regarding his father's orders, to whom he holds a deep obligation as his eldest son and heir.
The truth about Grevil's work as a detective is that it is an "aristocrat's hobby", and he had forced the local police to make him a detective purely because he had an interest in crime. In fact, Grevil is actually a terrible detective; one of the most notable mistake he made was how Grevil had suspected Kujo and nearly criminalized him for killing a government worker who was really killed by his lover, which would have caused a diplomatic war between Sauville and Japan. As a result, usually dependent on Victorique's intelligence to solve his crimes.
He shares a complex relationship with his younger half-sister, Victorique. In spite of his constant visits to Victorique, he is reluctant to interact with Victorique, especially since he knows that she can be overly demanding when it comes to repaying her talents. For example, his odd hairstyle. He also tends to say cruel things to her - for example calling her heartless, not knowing how to love. Despite that, does show that he cares for her, often protesting against his father's actions towards her and worrying about her.
He is in love with his best friend, Jacqueline, despite the fact that she is already married, and thinks very highly of her opinion.
- He owns a Bisque doll and keeps it on his desk at the police headquarters. In the anime series, it is a small doll about 18 inches tall, while in the manga, it is depicted as an almost lifelike replica of Victorique herself.
- Grevil has accustomed to calling Kujo a "Baby Squirrel".
- He is 205 cm (6 foot 7), being the tallest character in the series.