Season 1 of Remember 15 premiered on February 22, 2022.

A mystery message from "Lyla", a school star who committed suicide five years ago, was sent to her former high school classmate, seniors, and her sister. Everyone was wondering how this message was able to be sent, since Lyla had died a long time ago….

The 12 of them returned to the deserted island, the place where Lyla died five years ago… to pay tribute to Lyla and find out the truth about who sent the message to be a joke….

But the closer it gets to the truth the more they discover their cruel past. The dark secrets of the people they call “friends” have made this desert island become a bloody arena….