The newborn Kouga and Aria were found at the site of the crater having been bathed in Darkness and Light Cosmos. Kido Saori managed to take Kouga while Mars grabbed Aria. Realizing that the baby boy would have a harsh destiny because of the Darkness Cosmo inside of him, she decided to raise and bathe him in her own Light Cosmo in hopes that it would lead the child to a better future.
Several months after being born, as the baby Kôga learned how to walk, Mars returned, clad in a new armor called "Galaxy", to take Athena. In her effort to protect the child, Kido Saori was wounded by Mars' Darkness which prevented her from properly burning her own Cosmo, however before the God of War could take her, Seiya arrived to save them both. The young Kouga watched in awe as Mars and Seiya fought each other with all they had, ending up with the former severely wounded and the latter no where to be found.