Since the final episode of Produce 101 Season 2, the former members of I.O.I and Wanna One’s members decided to befriended with each other. Especially since almost half of them already friends, related or know each other before the show, such as Minhyun with Nayoung and Kyulkyung or Somi with Daehwi and Woojin. Seongwoo was in the same agency as Yoojung and Doyeon.  Even Yeonjung knew Jihoon from a short time when she was a trainee in SM Entertainment.