|Spoiler Alert: This page contains spoilers. Read at your own risk.|
|Full Name||Lucas Rozen|
|Occupation||Former Rozen Family Head Successor|
|Novel||Volume 13.5, Temptation of Rose (Mentioned)|
Lucas Rozen (ルーカス・ローゼン) is a member of the Rozen Family. He is the son of Bastian Rozen, the brother of the current Rozen Family Head, the father of Anna Rozen Katori, and grandfather of Chiba Erika. 
Even though he was reputed to be the most outstanding among his siblings, he was removed as a candidate to succeed his father as Family Head after it was discovered that he helped in the plot that allowed Georg Ostburg to flee during a terrorist incident in the United States when Lucas was fourteen years old and had setup for Georg to be his bodyguard. 
Ties to him were cut when he eloped with a Japanese women (Maiden name: Katori) and abandoned his fiancée that was chosen for him. This caused the Rozen trouble within European social circles, thus it allowed Maximilien Device the chance to do business in Europe. Though because of the close ties the Rozen have with the German government and military, they were unable to expand into the market, in Japan.