Yura, a young girl who struggles to fit in with her classmates, discovers an old smartphone while helping clean out a disused school building. Out of curiosity, she and her friends power it on. Soon afterward, strange videos featuring the children themselves begin appearing on their phones. At first, the clips seem like harmless jokes and are consumed much like viral internet memes. What the children do not realize, however, is that these videos are foretelling a horrifying future that awaits them.