The story follows Issei Hyodo, a dim-witted, lecherous second-year high school student who is killed by a girl on his first date ever. Issei is reincarnated as a devil, and from that day forward, he serves as an underling of Riasu, a high-level devil who is also the prettiest girl on Issei’s campus.

Staz is the vampire boss of a section of the demon world, but he has little interest in human blood. He’s more infatuated with Japanese culture. When he learns that Yanagi Fuyumi, a Japanese teenage girl, accidentally wanders into the demon city, he jumps to the occasion. However, while Staz deals with an intruder on his turf, the oblivious Fuyumi is killed by a monster and becomes a wandering ghost. The disappointed Staz vows to her that he will find a way to bring Fuyumi back to life.

In an alternate history of the Meiji era where humans and magical beings known as “younin” live side by side, half-younin girls team up with army lieutenants to fight younin wrongdoers.

In Victorian-era Europe, a young boy loses everything he once held near and dear to a vicious plot. In his moment of death, he strikes a deal with a demon: his soul, in exchange for revenge. Ciel Phantomhive is now the head of the Phantomhive corporation, handling all business affairs as well as the underground work for the Queen of England. His new partner is a demon butler, Sebastian Michaelis, whose powers as a butler is only surpassed by his strength as a demon. The story follows the two along with their other servants, as they work to unravel the plot behind Ciel's parents' murder, and the horrendous tragedies that befell Ciel in the month directly after.