Fictional Kingdom of Britannia, Middle ages. Ten years ago, the Holy Knights, led by Hendrickson, banished and eliminated the Seven Deadly Sins, seven knights who were alleged to have plotted against the king. However, soon the Holy Knights stage a coup d'etat and overthrow the king themselves, so the king's daughter, Elizabeth, flees and seeks the help of the Seven Deadly Sins. She first meets the short, blond Meliodas and his talking pig, Hawk, who are running a tavern as a disguise while searching the rest of their team. They encounter the other Sins: Diane, Ban, King, Gowther, Merlin. After Elizabeth gets kidnapped, the Sins attack the capital. It is discovered that Hendrickson injected demon blood into himself and the other Holy Knights and that he plans to break the seal and unleash demons again into the human world, hoping to have an enemy, and a purpose, for the Holy Knight. Meliodas defeats him and saves Elizabeth, while the king rehabilitates the Sins.
"The Seven Deadly Sins" are an anime series that starts off far better than it ultimately ends up to be. The first two episodes are so fantastic, fresh and creatively fun that you immediately ask yourself: "How can they possible keep up such a high level for the rest of the story?" Unfortunately, they cannot: the remaining 22 episodes are good, but routine. The first two episodes shine: a damsel in distress, Elizabeth, is looking for one of the eponymous Sins, Meliodas, in a tavern led by a short, blond teenager and his talking pig. Meliodas is depicted as a tall, dashing man with a goatee on a wanted poster. Throughout the entire episode, the name of the mysterious blond guy is never brought up. However, just as a knight thug chases and attacks Elizabeth, demonstrating his power that can level a quarter of the forest, he is confronted by the blond guy who defeats him. As the Holy Knight is catapulted in the sky, his armor destroyed, the blond guy then finally reveals his name—his image is "frozen" with a caption saying: "Meliodas, the sin of Wrath". And then the episode ends, with such a great, epic and cool cliffhanger. The 2nd episode also has grandeur thanks to a 'tour-de-force' sequence in which the evil Holy Knight Gilthunder throws a spear at a village located far away from his castle, but Meliodas intervenes, spots the spear in the sky and grabs it from a cliff: it plunges him into the village where it destroys half a house, but Meliodas is able to stop the spear and prevent any further casualties. Meliodas then catapults the spear back with equal ferocity, and it hits the castle, causing an explosion, hitting Gilthunder's chair—missing his head just by an inch. Unfortunately, once it builds up the viewers' appetite, waiting for further such 'tour-de-force' moments leads to no avail: "Sins" are riding on a false momentum for the rest of the storyline, exhausting its potentials from the start.
The anime basically undergoes a "Dragonball-ization", offering endless fights, wrestling and clashes, but they become boring and tiresome since the style and inspiration from the start is never repeated. The protagonists are stabbed, impaled or thrown through the walls several dozen times, almost "Tom & Jerry"-style, but since they always use their superpowers to regenerate again, there is no real tension or stake in these fights. It as if they are made of rubber. Another problem is that each subsequent episode introduces at least one or two new characters, overcrowding the podium, with no sense of timing or measure, while the old characters are forgotten and neglected. This is especially jarring in episode 12, where, all out of the blue, Elizabeth's older sister, Veronica is introduced, but killed in the same episode: the viewers cannot invest themselves into Veronica since she is just one of thirty characters that just come and go without any time to "grow roots" into the storyline. Episodes 9-11 are just empty filler, introducing a fighting tournament which the protagonists have to attend in order to get Diane's weapon, a hammer, as a prize, yet it ends in an illogical plot point: only the Sins are left, but instead of just faking it to not waste time battling each other and get the hammer, since they will get it as a team no matter who of them wins, Ban and Meliodas actually fight for real (!) as if their life depends on it. Other ideas are misguided: why is Diane a giant? It makes for a very inconvenient feature when she interact with the other Sins, and serves no purpose later on. She could have had normal height. A few better moments show up here and there, yet only in small crumbs: for instance, Ban, with a beard, escapes from prison, Jericho attacks him by wielding a sword, but it turns out she only managed to "shave" him, since he is invincible for the rest of his body. While the animation is beautiful (the two characters of Meliodas and Elizabeth are drawn irresistibly cute) and the main theme interesting—the good guys are actually bad guys who are fighting against the bad guys who are actually the good guys—"Sins" should have spent more care on its style and fun than its empty fights which seem standard. Ultimately, it is an anime that just pretends to be great, while it is truly great only in the first two episodes.