Young Ciel Phantomhive is known as "the Queen's Guard Dog," taking care of the many unsettling events that occur in Victorian England for Her Majesty. Aided by Sebastian Michaelis, his loyal butler with seemingly inhuman abilities, Ciel uses whatever means necessary to get the job done. But is there more to this black-clad butler than meets the eye? In Ciel's past lies a secret tragedy that enveloped him in perennial darkness—during one of his bleakest moments, he formed a contract with Sebastian, a demon, bargaining his soul in exchange for vengeance upon those who wronged him. Today, not only is Sebastian one hell of a butler, but he is also the perfect servant to carry out his master's orders—all the while anticipating the delicious meal he will eventually make of Ciel's soul. As the two work to unravel the mystery behind Ciel's chain of misfortunes, a bond forms between them that neither heaven nor hell can tear apart. [Written by MAL Rewrite]

The Abyss—a gaping chasm stretching down into the depths of the earth, filled with mysterious creatures and relics from a time long past. How did it come to be? What lies at the bottom? Countless brave individuals, known as Divers, have sought to solve these mysteries of the Abyss, fearlessly descending into its darkest realms. The best and bravest of the Divers, the White Whistles, are hailed as legends by those who remain on the surface. Riko, daughter of the missing White Whistle Lyza the Annihilator, aspires to become like her mother and explore the furthest reaches of the Abyss. However, just a novice Red Whistle herself, she is only permitted to roam its most upper layer. Even so, Riko has a chance encounter with a mysterious robot with the appearance of an ordinary young boy. She comes to name him Reg, and he has no recollection of the events preceding his discovery. Certain that the technology to create Reg must come from deep within the Abyss, the two decide to venture forth into the chasm to recover his memories and see the bottom of the great pit with their own eyes. However, they know not of the harsh reality that is the true existence of the Abyss. [Written by MAL Rewrite]

In 1972, a popular student in Yomiyama North Middle School's class 3-3 named Misaki passed away during the school year. Since then, the town of Yomiyama has been shrouded by a fearful atmosphere, from the dark secrets hidden deep within. Twenty-six years later, 15-year-old Kouichi Sakakibara transfers into class 3-3 of Yomiyama North and soon after discovers that a strange, gloomy mood seems to hang over all the students. He also finds himself drawn to the mysterious, eyepatch-wearing student Mei Misaki; however, the rest of the class and the teachers seem to treat her like she doesn't exist. Paying no heed to warnings from everyone including Mei herself, Kouichi begins to get closer not only to her, but also to the truth behind the gruesome phenomenon plaguing class 3-3 of Yomiyama North. Another follows Kouichi, Mei, and their classmates as they are pulled into the enigma surrounding a series of inevitable, tragic events—but unraveling the horror of Yomiyama may just cost them the ultimate price. [Written by MAL Rewrite]