Momoe Yamaguchi
On September 10, 2003, Onitsuka announced she would take a hiatus until the end of the year to undergo a surgery to remove polyps and get over poor throat condition. Shortly before the announcement, she finished the recording of "Ii Hi Tabidachi, Nishi e", the cover of Momoe Yamaguchi. The song was released in October 2003 and sold 83,000 copies, making it her sixth best-selling song. The song served as the theme song to West Japan Railway Company's Discover West campaign. In November 2003, she released "Watashi to Waltz o", which served as the theme song to the third season of the Japanese television drama series "Trick", as well as her previous hits "Gekkō" and "Ryūseigun". The song became her last single under EMI Music Japan.