Saint Seiya is a story from Masami Kurumada about warriors called ‘Saints’ whose task is to protect, and to fight against evil forces. There are also evil Saints in the story who are on the hostile side. It is said that every 200 years an evil will come back to earth and try to rule the world, and at the same time, the Goddess Athena will be reincarnated to prevent the evil from accesion to power on earth. The story has five main chacters: Seiya the Pegasus Saint, Shiryu the Dragon Saint, Shun the Andromeda Saint, Hyoga the Cygnus Saint, and Ikki the Phoenix Saint. The task of these Saints is to protect Athena, the Goddess of peace, and to defeat the evil forces. The Saints wear special armour, which each has deserved after years of hard training. Their armour not only protects them from external impacts, but also gives them special abilities. The armour represents a star constellation, from which a Saint also gains his power, called ‘cosmo’. The cosmo of a Saint is like an aura. According to the story, everyone has a cosmo, which he/she is able to discover.
Descriptions taken from AniDB.net