After the contest, musician and producer Tsunku offered Iida and four of the other runners-up (Natsumi Abe, Yuko Nakazawa, Aya Ishiguro, and Asuka Fukuda) the chance to be taken under his wing on one condition: that they sell 50,000 CDs of their song "Ai no Tane" in 5 days.
The group has since been increasingly popular in Japan, has achieved a cult following in the Western world and is infamous for its fluctuation of memberships, with members "graduating" and joining frequently.
In 1998, Tsunku placed Iida into subgroup Tanpopo with Aya Ishiguro and 2nd generation Morning Musume member Mari Yaguchi, and they specialized in singing slower, more mature songs.
After Morning Musume's then-leader Yuko Nakazawa graduated in the Spring of 2001, Iida took on the role as the group's leader.
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.
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.
On December 21, 2005, Iida released Plein D'amour: Ai ga Ippai, her fourth album.
Morning Musume Tanjō 10nen Kinentai also consists of Natsumi Abe, Maki Goto, Risa Niigaki and Koharu Kusumi.
She also performed at the Hello Pro Award '09: Elder Club Sotsugyō Kinen Special concert on February 1, 2009, which celebrated her graduation from Hello!
On July 6, 2007, Iida's agency announced that she was ten weeks pregnant and would soon marry Kenji, a former member of the disbanded 7 House, a band formed by Tsunku.
Iida began maternity leave after the Morning Musume 10th Year Anniversary Concert Tour: Summer '07 Thank You My Dearest on September 1, 2007.
[2][3][4] On February 3, 2008, Iida released a statement to her fan club that on January 22 at 10:30 am, she had given birth to a baby boy.