"Saint Seiya: Soul of Gold" is a 13-episode anime series that serves as a spin-off of the original "Saint Seiya" saga, focusing on the Gold Saints, elite warriors who serve as guardians of Athena. The story is set during the events of the "Hades Arc," specifically after the Gold Saints sacrifice their lives to destroy the Wailing Wall in the Underworld. Instead of passing on to the afterlife, the Gold Saints find themselves resurrected in Asgard, a realm connected to Norse mythology. They are unaware of how or why they have been brought back.

In Asgard, the Gold Saints discover that the realm is under the control of a corrupted god, Andreas Lise, who has usurped the throne of the true ruler, Lyfia. Andreas uses the power of Yggdrasil, the World Tree, to manipulate the souls of the dead and maintain his dominance. The Gold Saints, led by Aioria of Leo, must uncover the truth behind their resurrection and confront Andreas to restore balance to Asgard. Along the way, they face powerful enemies, including the God Warriors, who serve as Andreas's enforcers.

Each Gold Saint undergoes personal trials and battles, reawakening their divine powers and donning new God Cloths, enhanced versions of their armor that draw strength from the bonds they share with their comrades. The series explores themes of loyalty, sacrifice, and the enduring spirit of the Gold Saints as they fight to protect both Asgard and the world of the living. Key characters include Aioria, who takes on a leadership role; Saga of Gemini, who struggles with his dual nature; and Shaka of Virgo, whose wisdom and spiritual insight guide the group.

The narrative builds toward a climactic confrontation with Andreas, who reveals his connection to Yggdrasil and his desire to use its power to transcend the boundaries of life and death. The Gold Saints ultimately unite to challenge Andreas and his forces, culminating in a battle that tests their resolve and the strength of their bonds. The series concludes with the Gold Saints fulfilling their duty and ensuring the safety of both Asgard and the mortal world, though their ultimate fate remains tied to the larger "Saint Seiya" mythology.