The Nanatsu no Taiza Manga has a dark title, but it is, in fact, the lightest hearted series that is released by Kodansha in this year. It is more of a shounen that is aimed to young and teenage boys, and it falls in the same category with Fairy Tail and Sengoku's Dragon Balls. But with its nice art style, the manga can be enjoyed by any readers at all.
In the beginning, the story began in Brittania, a fantasy land where there are seven outlaws that grouped together and call themselves the Seven Deadly Sins. They wanted to overthrow the rulers 10 years before, and without anyone really knowing why, they just disappeared. The people are still aware that these people are still strong and ambitious, but they haven't shown themselves for a long time. The fight has resulted in a protectorate,named the Holy Knights, the fighters with magical skills that want to bring justice to the Seven Deadly Sins. If fantasy manga is your thing, we suggest you read Monster Musume no Iru Nichijou Manga
And then Melodias appears, a guy who is cheerful and ditzy who comes together with a princess who suddenly falls into his laps from the sky. And then the truth shows itself that the Holy Knights actually wanted to outthrow the king, while the seven deadly sins were the ones who tried to keep them out. The princess who is named Elizabeth is being chased constantly, so she seeks to find the lost warriors that were misunderstood, the ones who can help her raise the country again. So she falls into Melodias' arm, with his pig that can talk who carries his chipped sword. This guy, of course, has a few secrets of his own, which makes perfect senses because he has just come out of the forest.
The series features the type of conversations and art that are quite oldish, that is why you may not feel so familiar with it yet.