Ultimate Diamond
 Ultimate Diamond is the seventh studio album released by Japanese voice actress and pop singer Nana Mizuki on June 3 2009. It was released in two editions: a CD only edition and a limited CD+DVD edition. The first press of the album has a 44-page booklet. A limited CD+DVD edition of the album included a DVD of a concert at the Shinjuku Koma Theater on October 11 2008. At the concert she covered two enka songs: Fuyumi Sakamoto's Yozakura Oshichi and Mitsuko Nakamura's Kawachi Otoko Bushi.