After the release of the group's fourth single, Aya Ishiguro graduated from Morning Musume and left the group. The remaining members continued performing their songs in concerts as Generation 1.5 Tanpopo.
On June 2000, Morning Musume 4th Generation members, Rika Ishikawa and Ai Kago, joined Tanpopo, making the two-member group a four-member group. The style of their songs changed also when the four released "Otome Pasta ni Kandō." The style of this song became analogous to the songs Morning Musume had released. They also used this style on their next singles, which became popular and reached the number one spot on Oricon, and their second (and last) album.
On July 31, 2002, it was announced that Tanpopo was going to be completely reformed. Kaori Iida, Mari Yaguchi, and Ai Kago graduated from the group and were replaced by Morning Musume 5th Generation members, Asami Konno and Risa Niigaki, and Ayumi Shibata of Melon Kinenbi. This newly formed group only released one single before they went on indefinite hiatus.
| # | Title | Release date |
|---|---|---|
| 1 | Tanpopo 1 | 1999-03-31 |
| 2 | 2002-09-04 |
| # | Title | Release date |
|---|---|---|
| 1 | 1998-11-18 | |
| 2 | 1999-03-10 | |
| 3 | 1999-06-16 | |
| 4 | 1999-10-20 | |
| 5 | 2000-07-05 | |
| 6 | 2001-02-21 | |
| 7 | 2001-11-21 | |
| 8 | 2002-09-26 |
| Title | Release date | Company | ISBN |
|---|---|---|---|
| 2001-07-05 | Wani Books | ISBN 4-8470-2654-3 |
| Program | Radio station | Start date | End date |
|---|---|---|---|
| Nippon Hōsō | 1999-10-09 | 2000-03-25 | |
| 2000-03-30 | 2001-04-12 | ||
| TBS | 2000-10-03 | 2003-09-23 |