AKB48's Team Unknown is a temporary Team created for members that are promoted or transferred, but not to a specific Team. The system was first used with 10 members before the Team 4 formation, later with the 6 members promoted on June 24, 2012, before the Tokyo Dome Team Shuffle, and later with 25 members of HKT48 promoted on January 11, 2014, before the AKB48 Group Daisokaku Matsuri.