A 16-year-old boy named Marihu Shirota has a preference for simple things over complex ones. One day, he finds a stray black cat on the road and names it Kuro. This encounter sets off a series of events as a contract between Servamp Sleepy Ash (Kuro) and Mahiru is formed, leading to Mahiru being drawn into a servamp war involving seven deadly servamps with their eight sibling Tsubaki.
A 16-year-old boy named Mahiru Shirota, fond of simplicity and averse to comp...