Servamp

In Servamp, Mahiru Shirota is a 15-year-old who lives by one simple rule: troublesome things are best avoided. That cautious philosophy collapses the day he picks up a stray cat on his way home from school and names it Kuro, only to discover that the animal is far stranger than it seems. When a mysterious young man appears and sunlight forces Kuro to reveal his true form, Mahiru learns that the cat is actually a lazy vampire known as one of the Servamps, supernatural beings tied to the seven deadly sins. Kuro is the Servamp of Sloth, and before Mahiru can recover from the shock, a chain of mishaps leaves him forming a contract with his new freeloader, binding his fate to the vampire whether he wants to or not. As Kuro's Eve, Mahiru is pulled into the hidden rules that govern their world, where every Servamp is paired with a human partner and every alliance can turn dangerous. From that moment on, Servamp drags Mahiru into conflicts among Servamps, bloodthirsty beings, and uneasy alliances while he tries to protect the quiet life he wanted. The more he learns about Kuro and the other vampires around him, the harder it becomes to stay out of the struggle threatening both his home and the fragile balance around him.