Hello! Project Shuffle Unit

Hello! Project Shuffle Unit (ハロー!プロジェクト シャッフルユニット, Harō! Purojekuto Shaffuru Yunitto) was a Japanese idol project group formed by Up-Front Promotion in 2000 and associated with Hello! Project. Beginning in 2000, the Shuffle Unit project was a yearly collaboration among existing Hello! Project acts, where members were recombined into three different groups to release a single for each.
After a four-year hiatus, the project was briefly revived in 2009, where several old sub-groups saw a return under new names and new members. After 2009, the project became defunct.
Beginning in 2000, Tsunku created a music collaboration project with members of Hello! Project rearranged into three separate teams. The first theme, "color", consisted of Akagumi 4 (あか組4), Kiiro 5 (黄色5), and Aoiro 7 (青色7). All groups released their singles on March 8, 2000, with Akagumi 4's single "Akai Nikkichō" charting the highest at #2 on the Oricon Weekly Singles Charts.
In 2001, the groups were rearranged under the theme "party", with the three groups San-nin Matsuri (三人祭), 7-nin Matsuri (7人祭), and 10-nin Matsuri (10人祭). All groups released their singles on July 4, 2001, with San-nin Matsuri's single "Chu! Natsu Party" charting the highest at #5 on the Oricon Weekly Singles Charts. In 2002, the groups were rearranged under the theme "happiness", with the three groups Happy 7 (ハッピー♥7), Sexy 8 (セクシー8), and Odoru 11 (おどる♥11). All groups released their singles on July 3, 2002, with Sexy 8's single "Shiawase Desu ka?" charting the highest at #2 on the Oricon Weekly Singles Charts.
In 2003, the groups were rearranged under the theme "natural", with the three groups 7 Air, Salt 5, and 11 Water. All groups released their songs as a triple-A-side single on July 9, 2003. The project then took a brief hiatus in 2004, where Tsunku decided to promote all Hello! Project artists as "H.P. All Stars" instead.
Tsunku resumed the Shuffle Unit project in 2005, with groups rearranged under the theme "elegance." The three groups consisted of Sexy Otona Jan (セクシーオトナジャン), Elegies (エレジーズ), and Puri Puri Pink (プリプリピンク), all of whom released their songs as a triple-A-side single on June 22, 2005. Sexy Otona Jan's song "Onna, Kanashii, Otona" was later featured in the 2013 film The Wolverine.
On July 15, 2009, Tsunku revived the Shuffle Unit project with a cover album titled Champloo: Happy Marriage Song Cover Shū, describing it as J-pop with the intention of it being played during summer parties and weddings. He named the concept of the Shuffle Units "champloo" to describe the "chaotic" member line-up. The project also saw the revival of inactive or disbanded Hello! Project acts under new names with new members, including High-King, Mini-Moni (revived as Shin Mini-Moni (新ミニモニ。)), Tanpopo (revived as Tanpopo Sharp (タンポポ＃, stylized as Tanpopo#)), V-u-den (revived as Zoku V-u-den (続・美勇伝)), Petit Moni (revived as Petit Moni V (プッチモニV), ZYX (revived as ZYX Alpha, stylized as ZYX-α), and Aa! The Shuffle Units also released original songs on the Hello! Project's compilation album, Petit Best 10, and performed as concert-only units.
Member lists are adapted from Hello! Project's website: