Set in 19th-century England, the series focuses on a young earl named Cain Hargreaves who solves murders while encountering his father's secret organization, Delilah, that experiments with reviving the dead.

Cain's half brother and Alexis's illegitimate son, Jizabel Disraeli (ジザベル・ディズレーリ, Jizaberu Dizurēri) works as a doctor for the organization, conducting experiments on humans.

Although Alexis physically abused and emotionally traumatized him as well, he refuses to escape from him, and simultaneously despises and envies the bond between Cain and Riff as he believes unconditional love does not exist.

His thirty-five-year-old assistant Cassian (カシアン, Kashian), whose body stopped growing due to a rare strain of dwarfism and who was subsequently sold to a circus as a child by his parents, shows concern for Jizabel and his involvement with Alexis and Delilah.

After encountering Mikaila, who professes her one-sided love for him and wants to become Suzette, he becomes obsessed with destroying the organization and learns that it is secretly building a memorial temple.

Led by Cassian, whose brain has been transplanted into an adult body, he reaches the tower within the temple where Alexis plans to sacrifice the brainwashed people of London to revive Augusta.

It shows an elderly Mary, who lies on her deathbed attended by a woman nearby and hears the laughter of Jizabel's ghost as he plays with his pet sheep.

[2] Yuki considered Kafka, a vampire-themed mystery which introduced the secret society led by the protagonist's father, to be the beginning of the series' plot.

"[10] After completing the first four parts of Earl Cain (Forgotten Juliet, The Sound of a Boy Hatching, Kafka, and The Seal of the Red Ram), Yuki was uncertain about continuing the series.

[11] She wrote her supernatural fantasy manga series Angel Sanctuary (1994–2000) and the chapter "Solomon Grundy's Sunday" as a "self-introduction" which convinced her to start Godchild.

The first Godchild chapter, "Mad Tea Party", focuses on a mystery with elements from Lewis Carroll's 1865 novel Alice's Adventures in Wonderland,[16] a work which Yuki has expressed her fondness for.

As Yuki enjoys the American television series Twin Peaks (1990–1991), reviewers have noted its influence on Forgotten Juliet, the first part of Earl Cain.

[29][30] Yuki felt that two minor characters that appear in Forgotten Juliet, Maddi and Leland in the chapter "Branded Bibi", are reminiscent of the series.

[31] Yuki also drew inspiration from the film Young Sherlock Holmes (1985) for "The Boys Who Stopped Time",[32] and based the appearance of Cain's aunt on Charlotte from A Room with a View (1985).

[35] Additionally, Riff's name comes from The Rocky Horror Picture Show (1975), which Yuki considers a visual influence on her manga in general, along with the films Gothic (1986), The Legend of Billie Jean (1985), Aliens (1986), Lost Boys (1987), and Torch-song Trilogy (1988).

[40] Written and illustrated by Kaori Yuki, Earl Cain is the collective name for Forgotten Juliet, The Sound of a Boy Hatching, Kafka, The Seal of the Red Ram, and the sequel series Godchild.

[41] The chapters of Forgotten Juliet, The Sound of a Boy Hatching, Kafka, and The Seal of the Red Ram were published in five tankōbon volumes by Hakusensha from July 17, 1992, to October 1994.

[42] Hakusensha later combined chapters from Forgotten Juliet, The Sound of a Boy Hatching, Kafka, and The Seal of the Red Ram into two volumes and published them from December 20, 2004, to January 28, 2005.

[50][51] Earl Cain is also licensed for regional language releases in Germany and Sweden by Carlsen Comics,[52][53] in Italy by Planet Manga,[54] in Taiwan by Tong Li Publishing,[55] in Spain by Glénat,[56] and in France by Editions Tonkam.

[62] With music by Tomohiko Kira,[62] it featured Hideo Ishikawa as Cain, Koyasu Takehito as Riff, Kawada Taeko as Mary Weather, Miki Shinichiro as Dr. Allen, and Jūrōta Kosugi as Alexis.

The drama CD featured Hideo Ishikawa, Kyoko Hikami, Takehito Koyasu, from Kafuka and included Taeko Kawada and Junko Asami.

"[65] IGN's A. E. Sparrow described it as "a wonderful introduction to shojo manga for the uninitiated" and felt that both The Cain Saga and its sequel Godchild could "appeal to a very broad audience.

"[66] Conversely, Mania Entertainment's Danielle Van Gorder considered the art "still much less refined than her later work in Angel Sanctuary,"[67] and commented on the amount of tragedy in the series.

[69] In Manga: The Complete Guide, Jason Thompson rated the series two and a half stars out of four, stating: "In its best moments, The Cain Saga captures the genuine ghoulishness of the Victorian era, or at least of its stereotypes.

Writing for The Book Report, Robin Brenner described the mysteries as "unsettling, splatter-filled, and deliciously in line with the melodramatic, horrific traditions of Edgar Allan Poe and Mary Shelley.

"[76] In reviews of subsequent volumes, she lowered her score, and praised Yuki's characterization, mysteries, and artwork;[77][78] she concluded: "Godchild is a fantastic and different story that can't be denied.

"[81] While describing the series as "the manga equivalent of Twizzlers" and the premise as "ahistoric and just plain silly," Katherine Dacey of Popculture Shock added, "Kaori Yuki's distinctive artwork and macabre sensibility make this overripe setup entertaining, even if the occasionally slangy dialogue and CSI-style forensics seem implausible in a Victorian London setting.

"[80] According to Publishers Weekly, Yuki's art consists of "startlingly odd angles and abrupt jumps from closeups to distant shots" with which she establishes "a giddy mood" that enables the readers to be sympathetic to the events.