The characters will also look familiar: Tandoji, the brooding, self-doubting hero, who is afraid of his own power; Ruri, the absurdly rich and nice girl that needs his help, and her army of combat maids led by the mecha-riding super-efficient butler; the snarky infodumping comic relief; the mysterious black knight; the positive and energetic president of the Rock Club (rock as in pebble, not music), and assorted high school students. As the story progresses, we get to see some character development, specially from the hero, and there's plenty of annoying dialog to point it out very explicitly, in case the audience misses it.
The plot isn't specially complex, but the exposition is a bit jumbled, so don't be surprised if you don't quite get why some characters act the way they do, or struggle to remember one of the made-up terms they throw around. And the confusion will last for a while, because the main story advances slowly, frequently interrupted by relationship-building and plain high-school-anime filler.
In spite of its flaws, the show has its good moments. If you are looking for a straight-up, well-produced shounen, you could do worse than give Sacred Seven a try.
