As a result, Iida (along with Mari and Ai K.) graduated from Tanpopo. As with Hello! Project's shuffle groups, Iida was placed in punk-rock Aoiro 7 in 2000, folky festival style 10-nin Matsuri in 2001 and Odoru 11 in 2002, and ska-punk 11Water in 2003. She also participated in the 2004 summer shuffle group H.P. All Stars. In 2005, she participated in the shuffle group Puripuri Pink. She is the only member of Hello! Project to have participated in all the shuffle groups since the tradition started. Additionally, Iida is pursuing a solo career as an artist and singer. Her solo musical career includes two albums outside of Hello! Project where she sings covers of French, Greek, and Italian songs (in their respective languages). She also has two singles in Japanese, released in advance of her impending graduation from Morning Musume—though still set in a Mediterranean-esque style; many Western fans of Morning Musume and Hello! Project have described the style of Iida's solo material as "Euro-enka". In Morning Musume, Iida mostly sang harmony with a few solo lines. Her signature song in Morning Musume is "Yume no Naka", from the group's first album. On December 29, 2004, Iida released her third album, this time within Hello! Project and in Japanese. On January 30, 2005, Iida—the last First Generation member to still be in Morning Musume—graduated from the group to further pursue her solo singing and art careers. Mari Yaguchi took over her role as Morning Musume's leader upon Iida's graduation. Her tenure of over 7 years was the longest of any Morning Musume member, a record Iida would hold until January 2009 when fifth generation members Ai Takahashi and Risa Niigaki broke it. As of January 2009, she is one of only four members to remain in the group for over 7 years (4th generation member Hitomi Yoshizawa would later achieve this honor just weeks before her graduation in 2007 and 5th generation members Ai Takahashi and Risa Niigaki reached this mark in mid-September 2008). On December 21, 2005, Iida released Plein D'amour: Ai ga Ippai, her fourth album. This album featured songs in Japanese and many European cover songs in their original languages. This was her first album to be released since she graduated from Morning Musume. In early 2007, Iida was chosen to be a member of —a unit created to celebrate Morning Musume's 10th anniversary as a