"Saint Seiya: Tenkai-hen" is a four-part OVA series that serves as a continuation of the "Saint Seiya" saga, specifically following the events of the Hades arc. The story centers on the conflict between the Saints of Athena and the gods of Olympus, particularly Apollo, the Sun God, and Artemis, the Goddess of the Moon. The narrative begins with Athena and her Saints, including Seiya, Shiryu, Hyoga, Shun, and Ikki, ascending to the realm of the gods after their victory over Hades. However, their arrival is met with hostility, as the Olympian gods view their presence as a threat to divine order.

Artemis, acting as the enforcer of the gods' will, strips Athena of her powers and imprisons her. She also transforms Seiya into a stone statue as punishment for his defiance. The remaining Saints, determined to rescue Athena and restore balance, embark on a perilous journey to challenge the gods themselves. Their path leads them to confront Artemis and her loyal warriors, the Lunar Saints, who serve as formidable adversaries. The Saints must overcome these powerful foes while grappling with the moral and existential implications of defying divine authority.

As the conflict escalates, Apollo intervenes, revealing his grand design to reshape the world according to his vision. The Saints, driven by their loyalty to Athena and their belief in humanity's potential, stand against Apollo's overwhelming power. The series explores themes of sacrifice, resilience, and the clash between mortal determination and divine omnipotence. The narrative culminates in a climactic battle where the Saints must harness the full extent of their Cosmo energy to challenge Apollo and protect the future of humanity.

The main characters remain consistent with their established roles in the franchise. Seiya, the Pegasus Saint, embodies unwavering courage and determination. Shiryu, the Dragon Saint, represents wisdom and discipline, while Hyoga, the Cygnus Saint, balances emotional depth with combat prowess. Shun, the Andromeda Saint, showcases compassion and inner strength, and Ikki, the Phoenix Saint, brings raw power and independence. Athena, as the goddess of wisdom and war, serves as the moral and spiritual anchor for the Saints, while Artemis and Apollo represent the divine forces that test their resolve.

The series maintains the core elements of the "Saint Seiya" universe, including the use of Cosmo energy, the iconic Cloth armor, and the intense, high-stakes battles that define the franchise. "Tenkai-hen" expands the mythological scope of the story, delving deeper into the relationship between gods and mortals while delivering the action and drama that fans of the series expect.