Def.Diva (often stylized as DEF.DIVA) was a "special group" formed in 2005 from the Hello! Project idol umbrella, and consisted of Aya Matsuura, Maki Goto, Natsumi Abe and Rika Ishikawa. The band's name is an abbreviation of the phrase "Definite Diva". Three of the members of Def.Diva (Goto, Abe, Ishikawa) were previous Morning Musume members, while Matsuura is a soloist. Goto, Matsuura and Abe also comprised a previous three-member special group, Nochiura Natsumi.