Deathcord 

One day, Kyung-min, whose self-esteem has hit rock bottom from being bullied by his friends, suddenly receives an invite to "DeathCord," a chatting room where you can kill people through voting. Anonymous death penalty vote in the chat room! Anonymous participants invited to the chat room are keen to kill people for their own reasons. However, one of the chat participants becomes the target of the death penalty, after that, the participants in the "DeathCord" chatroom start struggling to identify each other... A murder game that won't end unless they kill each other!