| 'Standby IOI' is a sequel reality program showing the debut process of the members who were chosen through 'Produce 101.' It will be filled with every movement of the members who are preparing to release their debut mini-album on May 4 and actively promote. We will show their image on set of practice, photo shoots, and of course their recordings. |
| Name | Character | Episodes |
|---|---|---|
| Kang Mi-na | Kang Mi Na | 2 |
| Jung Chae-yeon | Jung Chae Yeon | 2 |
| Zhou Jieqiong | Zhou Jieqiong | 2 |
| Kim Do-yeon | Kim Do Yeon | 2 |
| Lim Na-young | Lim Na-young | 2 |
| Kim Se-jeong | Kim Se-jeong | 2 |
| Chungha | Chung-ha | 2 |
| Kim So-hye | Kim So Hye | 2 |
| Choi Yoo-jung | Choi Yoo Jung | 2 |
| Jeon So-mi | Jeon So Mi | 2 |
| Yeonjung | Yoo Yeon-jung | 2 |