Childhood friends Seunghwan, Dohee and Sangmin continue their cherished friendship even when they entered high school. However, they’re friend Sangmin disappeared due to the appearance of grosteque creatures called Goei (Gui)… As they search for their friend Sangmin, they found a few secrets… Will Seunghwan be able to recover his childhood friend? Geoki / Goei / The Monstrous / 괴이