Kallen Stadtfeld (カレン・シュタットフェルト, Karen Shutattoferuto) is a fictional character in the Sunrise anime series Code Geass: Lelouch of the Rebellion. In the series, she is legally known by "Kallen Stadtfeld" at school, but prefers her mother's maiden surname, using Kallen Kozuki (紅月カレン, Kōzuki Karen) during her revolutionary activities. Her voice actress Ami Koshimizu won "Best Actress in a Supporting Role" for her role as Kallen at the first Seiyu Awards in 2007. Kallen was awarded 8th place in the 29th Anime Grand Prix, then 17th and 16th, respectively, in the following two.