It appears as if Nikita Blank was sent into another dimension, completely far away from her original world. Trying to survive in an unknown place full of monsters called egos and defiled, a once anti-social girl started gaining new friends on the way to the dungeon's exit.
I suggest the author to not progress the story so fast. I feel like the story is about the canon only. It's still nice though. But at least make more side storylines. :)
There's quite a few chapters you need to read before you start to read the main plot but those chapters are short anyways so it kind of doesn't matter.