In the kingdom of Britannia, the Seven Deadly Sins are a group of powerful knights accused of betraying the kingdom before disappearing. Years later, Princess Elizabeth sets out to find them when the Holy Knights seize control of the country and threaten the royal family. She meets Meliodas, the leader of the Seven Deadly Sins, who agrees to help her reunite with his former companions. Together, they travel across Britannia, face numerous enemies, and gradually uncover the conspiracies, curses, and ancient conflicts that connect the destinies of Meliodas, Elizabeth, and the kingdom.