Class who dies from a mysterious explosion and is reincarnated into another world, not one but class
2In a world where the battle between Hero and Demon Lord repeated itself time and time again, an enormous space-time spell misfired and hit a certain Japanese high school class on Earth, killing everyone in it. However, guided by what seemed to be a miracle, the students were all reincarnated into that other world. While a handful was fortunate enough to become royalty, nobles, and other kinds of influential people, one girl was not so lucky. Being reborn as a spider monster of the weakest kind in a dungeon filled with vicious beasts, she is forced to experience extreme hardship. Even so, armed with nothing but her human knowledge and overwhelming positivity, she continues to press on and survive against creatures much stronger than herself.
The story follows a class who dies from a mysterious explosion and is reincarnated into another world; the class' pet spider is reincarnated as a dungeon spider. The spider evolves and ends up having a significant influence on the world, becoming one of its most powerful creatures, while the students and their teacher deal with the fallout from her actions and those of other armies.