The story begins on a rainy night, when a homeless little black cat is brought home by a young girl Luo Xiaobai. She names the cat Luo Xiao Hei. However, Luo Xiao Hei is no ordinary cat: he is a supernatural entity that hosts several small creatures called Heixiu. As Luo Xiao Hei new life soon threatened by the mysterious Diting, who commands three winged wolves. (Source: asiatvforum.com, edited)

Luo Xiaohei is a young monster who normally takes the form of a small black cat. Living freely in the forests, gradual deforestation and human development force him to flee and find a new home. Wandering the city streets, the black cat struggles to survive until he encounters Feng Xi, a fellow monster who takes Xiaohei to an isolated island inhabited by a small group of monsters. Excited to find what he thinks is his new home, Xiaohei lives with the monsters for only a short time before Wuxian, a human Guild Executor, arrives on the island in pursuit of Feng Xi. Feng Xi and his companions manage to teleport off the island, leaving Xiaohei and Wuxian alone. Though Xiaohei refuses to cooperate with the man who attacked his friends, Wuxian forces the black cat to travel to the Guild along with him. Embarking on an uncertain journey, Xiaohei is exposed to a new perspective on the relations between humans and monsters in a rapidly changing world.

In this world, angels, demons, and other supernatural beings peacefully coexist with humans. Neil Bowman is a demon who is unlike most; he is mesmerized with human culture, and no matter how hard he tries, he can't do anything evil. Thus, he runs away from Hell and up to Earth. Neil moves in with his online friend and vampire, Ira Blood, along with Ira's many roommates. Despite coming to Earth to meet humans, Neil discovers that not a single one of his new roommates is actually human. Along with Ira, there's Lynn Angel, the stern angel landlord; Lynn's little sister, Lily, who falls from Heaven; Abu, a mummy who never speaks; and Vladimir Eliot Kirilenko, a werewolf tasked with monitoring Neil. What most of them don't realize—not even Neil himself—is that Neil possesses the powers of the Demon King. What effect will this have on the residents of Apartment 1031 on All Saints Street?

"Dear Mom and Dad, it's already been a year since I left home. Don't worry- I'm doing great! I can take care of myself now. And I've learned to take care of others, too. Before, I never could have imagined having so many friends. But now, I can hardly imagine living without them. I think... Here, is my second home." It was all a lie. Suspicion. Betrayal. Conspiracy. (Source: PV)