From the introduction: Welcome to the world of Remnant, a land full of monsters, darkness, and cute girls with badass weapons. Humanity is embroiled in a permanent war against the dreaded creatures of Grimm. Mankind is forced to barricade themselves within massive cities to protect themselves lest they be overrun. Using their auras, the lights of their souls, in conjunction with Dust, the manifestation of nature’s wrath, the people of this world combat these monsters. Special combat academies train normal teenagers into Huntsmen and Huntresses, capable of wielding powerful weapons and using their unique semblances to bring the fight directly to the never ending threat of the Grimm.