The Seven Deadly Sins were once a group of knights in the region of Britannia, who disbanded after they supposedly plotted to overthrow the Liones Kingdom. Their supposed defeat came at the hands of the Holy Knights, but rumors continued to persist that they were still alive. Ten years later, the Holy Knights staged a coup d'etat and captured the king, becoming the new, tyrannical rulers of the kingdom. The third princess, Elizabeth, then starts out on a journey to find the Seven Deadly Sins and enlist their help in taking back the kingdom.