A Deliveryman's Diary of Hunting Demonic Beasts

Hidden from ordinary people's sight, the city is both the pinnacle of technological civilization and a hunting ground for ancient monsters. The protagonist starts out as a clueless delivery worker. After a chance encounter pulls him into this hidden world, he relies on his talent, intelligence, and brutal choices to fight his way through this concrete jungle where humans and monsters coexist, uncovering earthshaking secrets concealed behind everyday reality.