I.O.I (; also known as IOI or Ideal of Idol) was a South Korean girl group formed by CJ E&M through the 2016 reality show Produce 101 on Mnet. The group was composed of eleven members chosen from a pool of 101 trainees from various entertainment companies: Jeon So-mi, Kim Se-jeong, Choi Yoo-jung, Kim Chung-ha, Kim So-hye, Zhou Jieqiong, Jung Chae-yeon, Kim Do-yeon, Kang Mi-na, Lim Na-young and Yoo Yeon-jung. They debuted on May 4, 2016, with the EP Chrysalis and actively promoted as a whole and as a sub-unit for less than a year. The group's concert titled Time Slip – I.O.I, which was held on January 20 to 22, 2017, marked their last group activity on stage. They officially disbanded at the end of January 2017 and returned to their respective agencies. History Pre-debut: Produce 101 and "Crush" In November 2015, Mnet announced their new survival show that would bring together 101 trainees from 46 entertainment companies to form a unit girl group with eleven members chosen by the viewers. The show premiered on January 21, 2016, and ended on April 1, 2016. Prior to Produce 101, some of the members of I.O.I gained recognition after appearing on other television shows: Kim Se-jeong was a contestant on competition show K-pop Star 2 in 2012, Jeon So-mi was a member of the 2015 reality survival show Sixteen, and Choi Yoo-jung appeared in the web drama To Be Continued. In September 2015, Jung Chae-yeon debuted as a member of DIA but temporarily withdrew from the group to join Produce 101. She also had a cameo appearance in the 2015 web drama Sweet Temptation. It was initially planned for the group to debut on April 1, 2016, with the song "Crush," which they performed as part of the finale of the show, but YMC Entertainment and Mnet decided to postpone the debut to better prepare the group's concept and choreography with a new song as I.O.I's debut single. Its genre was referred to as "Trapical Dutch Funk" (Hangul: ). On April 3, 2016, a representative gave details of the plans for the debut of the group. Instead of releasing a digital single as initially planned, I.O.I would be releasing an EP with various songs. It was also reported that the group would have their own reality show on Mnet. On the same day, the members greeted the fans for the first