Heterogeneous Boundaries

Humanity has never seemed to have a real enemy, and this situation will be completely broken one day eight years ago. Countless people were killed, and territory was invaded and destroyed. All this balance will be overturned... People start a new life in darkness, and their small lives seem meaningless. Until a "boundary" that protects people is opened, like a dawn in the darkness, illuminating everything, mankind sees a glimmer of hope. The "alien hunters" who challenge the "alien" hold sharp blades and fight only for the future in the dawn.