It's there in the tags and description, and (to a certain extent) you can also apply the 3-chapter rule. If one doesn't like a concept, one should let the people who do have interest in the concept rate it objectively. Alas, people will never abide by this, which is how you get the rating of this manga. Hell, it's somehow lower than that one manga.If you don't like something, don't read it. Or at least don't persist in its lecture. A simple concept, yet one that seems lost in many. Even worse if you think it'll suddenly change to fit your tastes (it may change, but for one that does, many won't)