Seiken ga Saikyou no Sekai de, Shounen wa Yumi ni Aisareru ~Fuuin sareta Maou ga Kureta Chikara de Seikenshi-tachi wo Engo shimasu~

Long ago, humanity was defeated in a war against demons led by four demon kings, and only managed to survive on what little land remained under the protection of seven holy swords. Humanity continues to fight against demons that attack them, wielding many "imitation holy swords" made in imitation of the seven sacred swords left behind by the goddess.