I.O.I's "Suddenly" — The Title Track of Their 10th-Anniversary Reunion EP

I.O.I's "Suddenly" — The Title Track of Their 10th-Anniversary Reunion EP

"갑자기 (Suddenly)" is the title track of "I.O.I : LOOP," the third mini album by I.O.I, released on May 19, 2026. The EP marks the group's reunion for the 10th anniversary of their debut.

The Album and Its Members

I.O.I was formed through Mnet's "Produce 101" and debuted in 2016, wrapping up official group activities in January 2017. "I.O.I : LOOP" is their return after roughly nine years. Nine of the original eleven members took part — Im Na-young, Chungha, Kim Se-jeong, Jung Chae-yeon, Kim So-hye, Yoo Yeon-jung, Choi Yu-jung, Kim Do-yeon, and Jeon So-mi — with Kang Mi-na and Zhou Jieqiong absent due to acting commitments. The comeback was announced by Swing Entertainment.

The EP contains six tracks:

1. IOI (Where My Girls At)
2. Suddenly (갑자기)
3. SPF 100+ (Summer Pop Fantasy)
4. IF I
5. 그때 우리 지금
6. 웃으며 안녕

"웃으며 안녕" was released ahead of the album on May 4.

Concerts

Following the release, the "2026 I.O.I Concert Tour : LOOP" was held at Jamsil Indoor Stadium in Seoul from May 29 to June 1.