I.O.I, The 9-Year Miracle: Tops Melon Chart With 'Suddenly'

K-POP group I.O.I has reunited after nine years, and the comeback is reaching well past its core fandom into the wider Korean public.

On June 2 at 9 a.m. KST, 'Suddenly,' the title track from the group's third mini album "I.O.I : LOOP," sat at No. 1 on both the TOP100 and HOT100 charts on Melon, South Korea's largest music streaming service. The song had already hit No. 1 on the daily chart on May 30 and 31, the two nights of the group's first reunion concert.

Behind the chart climb was an unusual alliance between two fandoms. Until then, the top spot had belonged to boy group Cortis. In the days leading up to I.O.I's first concert on May 29, the group's fans, who call themselves "Yangdung-i," posted on X and other platforms asking Cortis's fandom, "Core," for help. Their request was simple: when you stream, add 'Suddenly' to the queue and give the song a lift. Reaction to 'Suddenly' was not warm at first. After the chorus was previewed on JTBC's variety show "Knowing Bros," some viewers said it sounded like trot and called it dated.

What turned the conversation around was the joy on the members' faces on stage and the story behind the reunion itself. Through YouTube shows such as "Salty Tour" (Jjanhanhyung), fans learned that the members had tried to reunite several times over the years but had been blocked by scheduling and contract issues, and that they approached this album thinking of it as their last shot. Word also spread that the group added an unscheduled appearance on Mnet's "M Countdown" the day before their concert, a move fans read as a sign of how much the members wanted to give back.

Online, the support has not slowed. Posting a clip of the members walking out at the concert opening, one viewer wrote that the audience's reaction sounded different from a normal show opening. "It felt like people were saying, 'Thank you for getting through these 10 years. We really missed you,'" the post read. "It made me tear up."

The most talked-about moment came on May 31, the last night of the domestic tour, when the members spoke through tears. "There were so many hard moments for all of us over the past nine years," Kim Sejeong said. "I'm so happy we're back together after growing up, getting stronger and healthier." Kim Sohye followed. "I tried to be perfect and it was so hard," she said. "But watching the fans cheer for me even when I messed up, I realized you don't have to be perfect. You just have to keep going." Im Nayoung said, "Mom, I became a perfect singer, right? I love you all," a line that pushed the crowd into open crying. Kim Doyeon added, "Honestly, I think I just really love singing and dancing. I know you can't only do what you love in life, but I'm not letting this go."

I.O.I originally debuted with 11 members through the first season of Mnet's audition show "Produce 101." In the nine years since, all 11, including Kang Mina and Zhou Jieqiong, have built their own careers. One has walked the red carpet at the Cannes Film Festival as an actor. Others have taken leading and supporting roles in TV dramas. Some have grown into recognized leads in musical theater.

The members who could not take part in this reunion still found ways to be present. Zhou Jieqiong, based in China, shared a video call with Choi Yoojung and posted a clip of herself dancing to a medley of I.O.I hits including "Pick Me." Kang Mina appeared in Jeon Somi's vlog on May 31, showing off a friendship that has lasted. Addressing past rumors of a falling-out among members, she told fans, "We talk every single day."

I.O.I sits in the memory of a generation of Korean viewers who watched the group form during their school years a decade ago. Fans have one wish for what comes next, and they have said it plainly: not every year, but every few years, come back. As long as that keeps happening, an entire generation gets to revisit a piece of its youth.