She rose to fame in the drama Kimi wa petto (2003) with Jun Matsumoto and gained huge popularity. Her first international film was The Last Samurai (2003) where she played Taka, wife of a Samurai slain by the character Nathan Algren, portrayed by Tom Cruise, Koyuki was well-known in Japan for years before that. She first caught the attention of the public in 1997 by winning an exclusive modelling contract with the magazine Non-no, but quickly grew beyond modelling and has earned acclaim as an actress through her many roles on Japanese television and in several Japanese films. She has been appeared in many commercials, including Coca-Cola Japan's Sokenbicha, P&G Max Factor SK-II, and Suntory Kakubin.