Hello! Project Shuffle Unit (ハロー!プロジェクトシャッフルユニット) was the name given to special annual units in Hello! Project composed of mixed members from current major units. Beginning in 2000, Shuffle Units were created for the purpose of shuffling around these members for releases and concerts as well as to promote friendly competition with a season-long collaboration to see which shuffle unit was able to sell the most copies of their single. By 2003, the competition idea was dropped and unit songs were all sold on the same single.