Hello! Project Shuffle Unit

 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 shuffled into three groups for a single release. The project became defunct after 2009.
History.
2000-2005: Initial beginnings.
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 , , and . 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 , , and . 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 , , and . 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 , , and , 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".
2009: Champloo.
On July 15, 2009, Tsunku revived the Shuffle Unit project with a cover album titled "Champoo: 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, Tanpopo, V-u-den, Petit Moni, ZYX, and Aa!
Members.
Member lists are adapted from Hello! Project's website: