Legends tell of young men who wear armor known as Cloths and fight using energy known as Cosmos, in service of the goddess Athena. They are known as Saints. In Japan, two Saints fight in a colosseum for an audience, with the host, Saori Kido, waiting for the Pegasus Saint. In Athens, Greece, a Japanese young man known as Seiya fights his rival Cassios, cuts off his ear and defeats him with his Meteor of Pegasus to earn the Pegasus Bronze Cloth. Later that night, before Seiya can return home, Cassios' master Shaina tries to kill him for revenge. Seiya wears the Pegasus Cloth and actually injures Shaina, but for a moment, he is unable to master the Cloth and his Cosmos. Shaina's men arrive to finish Seiya off, but thanks to his teacher Marin's advice, he turns the table and defeats her men with his Meteor of Pegasus technique. He also is able to break Shaina's mask to reveal her face. The next day, Seiya heads back to Japan.

The Bronze Saints in the colosseum, Lionet Ban and Unicorn Jabu, continue their tournament match, with Jabu emerging as the victor. Seiya returns and demands to see his long-lost sister Seika after training for six years in Greece. Saori's grandfather promised him that he would see her if he retrieved the Cloth. Saori Kido, granddaughter of the late Mitsumasa Kido, leader of the Graude Foundation, and host of the Galaxian Wars tournament, offers Seiya a deal: if he wins the tournament, the Foundation will find his sister. With words of encouragement from his childhood friend Miho, Seiya decides to participate in the tournament, since it is broadcast worldwide and his sister might be able to see him on television. Seiya's first opponent is Bear Geki, and because of his arms, Seiya seemed like he would die from strangulation. But thanks to his master Marin's teachings of defeating an opponent by crushing their greatest weapon, Seiya breaks Geki's arms, the source of his strength, launches hundreds of kicks and comes out victorious.