IOI's 10th anniversary concert title track '갑자기' hits #1 on music charts; concert airs on MBC June 13

IOI's title track 갑자기 ("Suddenly") topped the music charts on the day of the group's 10th anniversary concert. It was the nine-member group's first full reunion on stage in nine years.

Formed through the 2016 audition program Produce 101, IOI was active for approximately eight months. They earned music broadcast wins and rookie awards during that stretch. The 10th anniversary concert brought all nine members back together, coordinated across their respective agencies, with each member's management contributing staff to make it work.

The setlist spanned Pick Me through Downpour (소나기), drawing from their original active period. Member Jung Chaeyeon was in tears backstage before the concert. She spoke about anticipating the reunion with fans—and the possibility that this might be the last time.

MBC's Omniscient Interfering View (전지적 참견 시점) will air concert footage as the centerpiece of episode 402 on June 13 at 11:10 PM.