A spin-off of the manga series Saint Seiya by Masami Kurumada, it first started being serialized in the monthly magazine Champion Red on December 19, 2002, and was concluded on June 19, 2013, being later compiled into 20 tankōbon by Akita Shoten.

It takes place in a fictional universe where the Olympian gods cyclically reincarnate on Earth, often waging war on each other for dominance, and depicts the battle of the Gold Saints, warriors with superhuman powers who fight for Peace and Justice in the name of the goddess Athena to protect the Earth from the recently awakened Titan gods.

[4] Their first assault is thwarted by Aiolia, who subsequently gains the attention of the Titans as the "man of the evil omen" who is destined to free their King.

In the course of their next assault, Kronos is inadvertently released from Zeus's lightning seal by Aiolia's own lightning-based technique, but the god appears to be amnesiac.

The Titan King robs Gaia of his power, offering it to Hades instead so that the Saints of Athena and his followers will be spared from death.

[7] In the author commentary page published with the first volume, Megumu Okada explained that he had concerns about taking on the project because he had never written anything that was related to a pre-existing original work and because Saint Seiya was such a renowned piece.

[9][10] This resulted in a manga that is, visually, substantially different from its predecessor: character designs are slim and androgynous[11] and details are enhanced to an extreme.

[12] The first images of the manga appeared in the Champion Red magazine issue of January 2003, published on November 19, 2002, along with posters by and an interview with Masami Kurumada.

Voice actors include: Hiro Shimono as Leo Aiolia, Hikaru Midorikawa as Aquarius Camus, Kōji Yusa as Galan, Chiwa Saitō as Lithos, Kōsuke Okano as Okeanos and Hiroki Yasumoto as Pontos.

[35] In December 2013, Megumu Okada announced via Twitter that he was working on a sequel manga titled Saint Seiya Episode.G: Assassin.

While the manga is full of references to Saint Seiya, the story is based on the same known schemes and the characters are too similar to the protagonists of the original series.

[50] Meanwhile, for Brazilian critic Pedro Hunter of Omelete, Episode.G sets itself apart from the usual shōnen manga by not featuring only endless battles and undeveloped storylines.

[52] In a later review, however, it is also noted that Episode.G retains the spirit of the original series, successfully portraying the emotions present in battles between warriors who can respect their opponents and admire their willingness to give their lives for what they believe is right.

[53] Generally praised as "impressive" is Okada's graphical skill, his use of composition and textures which enhance the divine aspects of the characters, although critics also note that the heavy amount of detail in a black and white manga often interferes with readability.