You download this app called Mystic Messenger to talk to cute boys and suddenly this person with an "Unknown" username has suddenly started telling you to go to some apartment to return the phone! Once Unknown helped you (practically break in) get into the apartment, your phone gets spammed by the Matrix and suddenly...
Y/N and Seven have been bestfriends ever since they were little, yes childhood friends. Y/N was homeless, so she was in an orphanage and played with Saeyoung when they went to church. Saeyoung has never introduced Saeran to Y/N, so she doesn't even know if Saeyoung even has a twin. But one day, Saeyoung dissapeared...