The seven deadly sins are a band of knights who were disbanded after being framed for plotting a coup of the Kingdom of Liones ten years before. The one who sequestered them was the Holy Knights and then taking control of the kingdom in the wake of the rebellion they organized. Liones’s third princess Elizabeth Liones escapes from the holy knights in search of the seven deadly sins whom no one has seen them after ten years seeking their help. While running away from the knights she ends up the Boar Hat tavern where she meets with a young boy who seems to be the owner of the tavern. He reveals himself as Meliodas, the Sin of Wrath, and the bearer of Dragon symbol and also the captain of the Seven Deadly Sins.

Meliodas agrees to help Elizabeth to look for the other sins since he is also searching for them. The second one they find is Diane, the Serpent’s Sin of Envy. She belongs to the Giant race and she hid herself in the Forest of White Dreams. Together with Diane they go to the Baste Prison where the Sin of Greed Ban and the bearer of Fox symbol is being imprisoned. On the way they were attacked by the Holy Knights which they defeat them. At the Baste prison, Ban breaks out of the prison when he hears about Meliodas and meet with him. The third person they find is King, Sin of Sloth and the bearer of Grizzly bear symbol.

Later they meet with Gowther, the Sin of Lust symbolized by Goat symbol. Later the princess Elizabeth was kidnapped by the Holy Knight. To rescue the princess they go back to Liones Kingdom where they came to know that a demon named Fraudrin was manipulating the Holy Knights by possessing the body of a Holy Knights. Fraudrin aim was to unseal the Demon Race from prison whom they were sealed 3000 years before by the God race. During the encounter with the demon they meet Merlin, Sin of Gluttony and the bearer of Boar symbol. By knowing that they were being used by the demon Holy Knights sides up with the deadly Sins and defeats the demon.

But the demon somehow manages to escape and unseals the prison releasing the Ten Commandments who has received the power from the Demon King. The sins and the knights fights against the commandments who is led by Zeldris. During the encounter with the commandments Deadly Sins was joined by the seventh Sin Escanor, the Sin of Pride and the bearer of Lion symbol. Escanor is considered to be the strongest one among the Seven Deadly Sins.

Later others get to know that Meliodas is the son of the Demon King and was cursed with eternal life and has been living around 3000 years. The one commanding the Ten Commandments was Meliodas’s brother. Meliodas also reveals that Elizabeth is from the God race and also is cursed with reincarnation. When she was reborn she will not have any memory about her past but when she regains that memory she will die at the third day after she regains her memory. Meliodas goal is to break this curse of theirs. For that he has to become the Demon King.