Ai Takahashi played the lead role, Sapphire, in the musical "Ribbon no Kishi The Musical" which was a collaboration work of Takarazuka Revue (a famous Japanese all-female musical group) and Hello! Project. The musical was based on Tezuka Osamu's manga and also starred v-u-den, Nozomi Tsuji, Aya Matsuura, and Natsumi Abe, as well as Marcia and Kaoru Ebira of the Takarazuka Revue. Soon thereafter, Takahashi released her first and only solo single to date, "Yume Kara Samete", Following then-leader Hitomi Yoshizawa's graduation from Morning Musume on May 6, 2007, the current sub-leader, Miki Fujimoto ascended to the leader position, with Takahashi becoming the new sub-leader of the group. However, on June 1, 2007, after Fujimoto's resignation, Takahashi took over as the new leader.
