Koyuki appeared in Kiyoshi Kurosawa's 2001 film Pulse. Her first international film was The Last Samurai where she played Taka, wife of a Samurai slain by the character Nathan Algren, portrayed by Tom Cruise. She also appeared in Blood: The Last Vampire live-action film starring Jun Ji-hyun, where she plays Onigen, the arch-villain.
In 2011, Koyuki married actor Kenichi Matsuyama, who co-starred with her in Kamui Gaiden. The couple's first child was born in January 2012, and their second child was born in January 2013 in South Korea. In July 2015, the couple had their third child.
