In 2006, "Princess Knight" was adapted into a musical, , and performed in Japan by members of the popular idol groups Morning Musume and v-u-den with Ai Takahashi in the lead role. Directed by Shinji Ueda, with screenplay by Shinji Kimura and music by Masato Kai, it played at Shinjuku Koma Theater from August 1 to 27. The Up-Front Works record label Zetima released a music collection and a DVD of the musical on July 26, and November 29, 2006 respectively. Later, on December 25, its television broadcast was done by BS Japan.