One day you was walking somewhere when you suddenly got injected and fainted. You woke up in a strange room with your enemy and class rival Hyunjin.

"Finally you woke up" he said in an annoyed tone "What type of prank are you playing now"

Speaker: Hello both of you. Welcome to 100 days challenge both of you were selected to try this out. 100 days in this room. No escape. Unless you press red button and both die. You'll get 5mil$ if you survive. Now let's begin.