Seven years before the events at the focus of the series, one hundred orphans from Japan are sent to different parts of the world to become a saint of Athena. The story focuses in one of these orphans called Seiya. He is sent to the Sanctuary in Greece to become the Pegasus bronze saint.
After seven years Seiya becomes the Pegasus saint and returns to Japan to find his older sister. Because her sister disappeared the same day Seiya went to the Sanctuary, Saori Kido, the granddaughter of the person who sent all orphans to train but died a few years ago, makes a deal with him to go to fight in a tournament called the Galaxian Wars where the orphans who survived and became bronze saints must fight to win the most powerful cloth: The Sagittarius gold cloth. If Seiya goes to compete there, Saori would start a search to find the sister of Seiya.
During the series the Seiya becomes the partner and friend of the other bronze saints: Shun, Shiryu and Hyoga. As the myth of the saints they must fight together to protect the reincarnation of Athena from any danger.