Sokcho had been home to thousands of humans for a long time but peace was never a state its people could live in. When the Korean War ended, everyone thought they could finally be able to breathe in fresh air, untainted by the smell of blood they were forced to get used to. However, maybe peace was not meant for Sokcho because even after nearing 70 years, war was still being fought, only their enemy now was not mankind anymore. The Bloodsuckers, a species that lurked around town at nights and blended in with the society during the days, had their own fight between themselves. When majority of the clan respected mankind and was willing to live together in harmony, there was a number of them who saw humans as their food. Feeling like they should be in charge, these 'rotten' Bloodsuckers had been murdering people, quietly at first but as they had gotten braver, it was clear that they did not want humans to be governing Sokcho, or the world even. 

The 7 Slayers (who obviously do not call themselves that but i do bcs it's cool), is a group of high school boys who hunts Bloodsuckers to seek revenge after the death of a family member. Jaebum was the one who suggested hunting these creatures down to help Mark avenge the death of his sister. Along with Jackson, Jinyoung, Youngjae, BamBam and Yugyeom, the seven of them promised to work together to slay all Bloodscukers including Mark's sister's murderer. Mark realised what his friends were doing for him was very dangerous. Nevertheless, he could not help but feel glad that Jaebum understood his grief and was willing to sacrifice his life for this. 

But one night, Jaebum came back from hunting with a secret that changed everything; the girl sitting next to him in class, Byul, might be the Bloodsucker who killed Mark's sister. What he gon do now damn dis is where the drama starts ciao see yalls in chapter one.