Survival Manual for a Girl's World

A fic on how to survive in a girl's world, continuing the ending where you can't get up and get down. Katagiri is the only boy in the girls' school, and he's actually been exposed? ! The silly and sweet classmate, the senior who acts like a machine, the half-sister, and the fierce-looking senior, why are they all surrounding me! What are you talking about, there are still robots trying to figure out all of humanity? In a desperate situation, if you don't survive, you will die!