Seiya intends to find his sister who disappeared the day he left, but Saori makes a deal with him: if he competes in the Galaxian Wars and wins, she'll help him find Seika. Kido is the granddaughter of the late Mitsumasa Kido, the man that sent Seiya to Greece, separating him from his sister Seika.
Years later, after gaining possession of the Pegasus Cloth, a mythical armor protected by said constellation, he returns to Japan and meets up with Saori Kido.
Seiya is an orphan child that was sent to the Sanctuary of Athena in Greece, where he underwent training to become one of the Saints of Athena.
