From Yen Press:
Legend speaks of seven heroes, each one bearing the power of one of the stars of the Big Dipper. Two of these stars are constantly in conflict, destined to battle and throw the world into chaos. Not that Taitou has ever paid much attention to old stories. Headstrong and defiant, he is the last in his village to complete his coming-of-age ceremony, a fact his sister Laila incessantly teases him about. When he is finally deemed worthy, he is presented with the Kenkaranbu, an ancient sword that can only be drawn by a true hero. As the frustrated Taitou struggles to unsheathe the sword, a mysterious thief appears, making off with the blade and citing the legend of the Big Dipper. The stars have been set in motion, as Taitou sets off after the Kenkaranbu and the truth of his own destiny.