Joo Seung-ho is unable to do virtual reality due to ’congenital hyperimmersion syndrome’, a phenomenon of excessive sensory amplification.One day, a string of unknown colors comes down to him.It is the tester of the 4th generation VRS’ device!When he was able to do virtual reality by becoming a tester, he thought for the first time.That what he caught was a rope made of gold.When he experienced Lost Sky Online’, commonly referred to as the 4th generation, he realized it.The congenital hyperimmersion syndrome’ was a poison in the past, but it was actually a blessing.It’s time to change into a new him’ that was different from his usual self.[Welcome to the world of the Lost Sky.]