From January 20 to 22, 2017, I.O.I held their final concert titled Time Slip – I.O.I. The three-day concert was held in Jangchung Gymnasium, where the group held their debut showcase.

To celebrate their fifth debut anniversary, the I.O.I members reunited for a highly anticipated live broadcast!

Have you kept in contact with your good friends from youth? Are they all doing well? Housewife Zhang Lijun reunites with her high school friend Lin Qing who is seriously ill in the hospital. Lin Qing hopes to be reunited with her old friends before her death. Zhang Lijun starts a journey to find their old friends. Along the way, everyone regained their youth and re-examined their current life.