"Saint Seiya: Saintia Shō" is a spin-off of the original "Saint Seiya" series, focusing on a group of female warriors known as Saintias, who serve the goddess Athena. The story is set in the same universe as the main series but shifts its perspective to the Saintias, who are tasked with protecting Athena and maintaining peace. The protagonist, Shōko, is a young girl who becomes a Saintia after being saved by Saori Kido, the reincarnation of Athena. Shōko's journey begins as she trains to harness her Cosmo energy and earn her Cloth, the armor worn by Athena's warriors.

The narrative unfolds as Shōko and her fellow Saintias face various challenges, including battles against rogue Saints and other enemies who threaten Athena's safety. The Saintias are not frontline fighters like the Bronze Saints but play a crucial role in safeguarding Athena and supporting the main warriors. The series explores themes of loyalty, sacrifice, and the bonds of sisterhood among the Saintias as they navigate their duties and personal struggles.

Key characters include Shōko, who is determined to prove her worth as a Saintia; Saori Kido, the compassionate and wise reincarnation of Athena; and the other Saintias, each with unique abilities and personalities. The antagonist, Eris, the goddess of discord, poses a significant threat, seeking to sow chaos and undermine Athena's efforts to maintain peace. The conflict between Athena's forces and Eris's followers drives much of the plot, culminating in intense battles and strategic confrontations.

The series incorporates elements of mythology, fantasy, and action, staying true to the "Saint Seiya" universe while offering a fresh perspective through the lens of the Saintias. It balances character development with dynamic fight sequences, providing a comprehensive look at the roles and responsibilities of Athena's female warriors. The story maintains a focus on the Saintias' growth, their relationships, and their unwavering dedication to their mission, making it a distinctive addition to the "Saint Seiya" franchise.