Kumo desu ga nani ka

In another world the Hero and the Demon King continued to oppose each other As their great magic collided the explosion crossed over worlds and destroyed a classroom full of high school students The victims who died in that explosion will be reincarnated in that alternate world Our heroine who has the lowest standing in the class was reincarnated into a spider She nevertheless faces this challenge headon with great determination and adapts to it surprisingly quickly
This is the story of how our protagonist who was reborn as a weak spider monster does whatever needed to survive