In September 2000, Katja Kassin started working as a nude model posing for local amateur photographers and websites. She adopted the first name "Katja" as her pseudonym at the suggestion of the photographer at her first nude shoot, after his niece. After three years, she moved into softcore shoots and eventually came in contact with German porn star Dru Berrymore. Kassin was introduced to Mark Spiegler of the talent agency Spiegler Girls. Her first scene in the United States was filmed in March 2003; before that she had only done two scenes in Europe. She permanently moved to the Los Angeles area in late 2004 and married a fellow male performer in January 2004.