[Blank girl + apocalypse + superpower + non-collapse combat power + adventure + decryption + multiple heroines]
The story is set some time in the future.
The alien life form "Cheer" invaded the earth, and the nuclear weapons were exhausted, but there was still no victory.
Artificial intelligence and military robots are also difficult to resist.
Alien creatures have various powers and powerful perceptions, and only infrasound waves can interfere with them.
The only remaining humans use infrasound waves to build fortresses in various places. The fortresses are called "Char", and humans struggle to survive in "Char".
However, infrasound waves cannot interfere with the advanced "Cheer", and human survival is still threatened.
I am a fortress builder, and at the same time, I am continuing my father's unfinished research on the application of sound waves.
But after a long period of resistance, mankind will give up the fight. At the time of human survival, the female descendants of certain races on the earth have unleashed powerful abilities and are known as "witches."
Witches have all kinds of nonsensical powers. Among them, a witch that is parasitic on human physiology has also begun to be liberated.
Me, on an ordinary night, because of an unexpected coincidence.
I! He was actually touched by the evil witch.