Synopsis: Paradise fantasy land

Shinyul rides the last train on the subway and arrives at Geungnakseong Station, which he has never seen before... In this mysterious and colorful place, he meets Seongju Baek and Blue Dragon. What is the identity of the two and Shinyul, who already know Shinyul, and what is their fate in the paradise castle that turns into a terrible he** when the full moon rises?