Yasuda, along with Mari Yaguchi and Sayaka Ichii, were the second generation of singers to be recruited into Morning Musume.
After they joined, Morning Musume went on to produce one album and three more singles until Asuka Fukuda decided to leave to pursue her studies.
Yasuda and Ichii sang a particularly catchy duet known as "Otome no Shinrigaku" (Girl's Psychology) on Morning Musume's second album.
In response to the popularity, Tsunku decided to group them together with the third generation member, Maki Goto to create the Morning Musume subgroup Petitmoni (also known as Pucchimoni) in 1999.
After Ichii left Morning Musume and Petitmoni, fourth generation member Hitomi Yoshizawa joined the subgroup.
After Morning Musume's then-leader Yuko Nakazawa left in 2001, Yasuda (who was the oldest member of the group at the time) became a co-leader along with Kaori Iida.
Additionally, as a special gift, Tsunku gave Yasuda a CD of her own solo version of "As for One Day," her last single with Morning Musume.
Within H!P, she has collaborated with Nakazawa and other H!P artists on two Folk Songs albums, performed and MC'd Abe's first solo concert, sang backup on Goto's single "Daite Yo!