Shoko is a middle school student who goes to Ryusei Academy. Her older sister, who she was very close to, went to study overseas five years ago and hasn't been heard from since. One day, Shoko is attacked by a Dryad, a servant of the evil goddess Eris, who had been sealed away by the goddess Athena. Learning about Athena, Saints, and Saintias, as well as the cruel destiny that was thrust upon her sister and herself, Shoko decides to fight against fate.