in chapter 5 memories 1 you find a description of the peculiarity, it is called essence

Do you need me to explain or answer any questions you have about the story?

no es harem

Thanks for your comment, I am trying to bring more content in the shortest time possible so I may have to rewrite some parts for better understanding, I will make an improved version of the first three chapters in the initial volume after bringing the first episode of volume two , so I will improve those chapters that I already have and I will try to bring a better understanding in the next arcs.