I.O.I, also known as Ideal of Idol, was a South Korean girl group formed through talent agency CJ E&M's reality show Produce 101 in 2016. The group consisted of eleven members selected 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. Chrysalis, their debut EP, was released in 2016 and climbed to Number 4 on South Korea's Circle Chart. Before their official debut, the group had planned to issue the single "Crush," but decided to release an EP with various songs instead. They held their debut showcase and fan meeting on the same day at Jangchung Gymnasium in Seoul. I.O.I released successful singles such as "Whatta Man (Good Man)" and "Hand in Hand," both of which entered the Top 10 in South Korea. In October 2016, they released an extended play titled Miss Me?, which included the radio hit "Very Very Very," earning them their first music program trophy on Show Champion. In January 2017, I.O.I announced their disbandment with a final concert series titled Time Slip – I.O.I. Their final track, "Downpour," was released that same month. Following disbandment, the members returned to their respective agencies. The group held a reunion livestream on the 5th anniversary of their debut in 2021.