Sixteen-year-old Emma finally reaches the capital city of Hawk Eye after escaping captivity that lasted her entire life. However, upon her arrival, every man in the city, including the king, falls madly in love with her. She is on the verge of being forced into marriage but is rescued by a sorcerer. The sorcerer introduces himself as Shion, one of the nation's youngest and most talented mages. They have met previously, though Emma has no memory of it. Shion explains to Emma that she is cursed with the Echidna, a mysterious magic that manifests once every 500 years. It involves the birth of a girl whose heart contains such potent dark magic that it holds the potential to destroy the world. With such power, one could rule the world, and Shion warns Emma that people will attempt to hunt her down to seize her heart. However, Emma is informed that a ritual exists to remove the Echidna's curse, though it requires a long and arduous process. The first step is that Emma and Shion must marry each other... Included one-shot: Volume 8: Karakuri Link