From the Wiki: "Olivier is a Fixer of Hana Association South Section 3"

Olivier is Roland's long-time partner (this is an actual quote from the game). In contrast to Roland, Olivier is very calm and collected man who prioritizes his work above all else. Despite this, he will still go out of his way and break a few rules if it meant helping out a friend. He puts a lot of value in his friendships and fondly remembers the time he had with Charles' Office, his old 'mercenary' group. Olivier is a cautious man, usually opting to take the most efficient and safe course of action in any situations. Because of this, he is usually the person who has to tug on people's collars to prevent them from doing anything reckless. But this prudence of his is also his downfall - he isn't someone who would plan to take risks. As he puts it in the game, "I had the prudence, and you (Roland) had the unhesitating action. We helped each other through our strengths, and we could just live on by dealing with matters at hand back in the day".

Other Notes:

• Examples of his voice can be found on my animatic here (there's no videos on Youtube that have his spoken dialogue - apologies!)
• Would like only Black VAs to audition for this role, thank you!