“I guess my confession would be that I joined the gang in hope of finding joy in killing others.”

Kai wakes up one morning to find his physical being gone. When trying to make contact with others, he appears invisible and soon he finds that he walks right through people. Only then he realises that he no longer exists. Wandering aimlessly, he expects to walk through Kyungsoo, but instead the two collide and only then he realises that Kyungsoo is just like him.