I get that people want to help and report content that they view as dangerous, especially content that includes underage, but i feel like overall people are VERY quick to jump the gun on whats actually considered CSEM.
I do not use the term CP, it is not the correct way to reference such material, so i will exclusively use CSEM / CSAM, just for reference throughout the rest of this post. I would also like to specify that i am American, and my understanding of the law purely applies to the USA, so your laws may vary! Make sure to do appropriate research for whatever country you may be in, but also keep in mind your laws will not apply to everyone you meet online.
As unsettling as the concept of fictional underage can be to some, and i do not judge you for your discomfort for such depictions, choosing to report it is a waste of resources that could be put to use helping real life children. I am not saying this to insult you or put you down, but if you are using government report forms for depictions of things such as lolisho or drawings of bnha characters, you are misusing these forms, as the government does not care about these depictions. This has nothing to do with morality, or what i think is okay vs what you think is okay, this is purely based in what the law declares CSEM.
Pulled directly from Justice.gov:
Visual depictions include photographs, videos, digital or computer generated images indistinguishable from an actual minor, and images created, adapted, or modified, but appear to depict an identifiable, actual minor.
What does this mean, exactly? How does it separate fictional minors from real ones? The use of "Indistinguishable" is one of the important phrasing details. Yes, a drawing can count as CSEM, but the depiction must be nearly to entirely photo-realistic. When using the phrasing indistinguishable from an actual minor, they are not referring to 'you can tell the drawing is supposed to be of a child', they are saying that the image needs to look like a real life photo of a child even though it was created by a person or a machine. If you can tell that it was hand drawn, it does not fall under the CSEM umbrella.
"Appear to depict an identifiable, actual minor" is the other important phrase here. More or less, this just references that you need to be able to point at a real life person who exists and go "yeah this is the kid in the image", even if said photo is edited to some degree or was drawn by hand. This is what separates things like lolisho from someone who is actively drawing real minors that they know in sexual situations.
These distinctions, while seeming small or like i'm purposefully cherry-picking meanings and phrasing, are very significant when it comes to the law. Law is picky, whether we like it or not, and phrasing can and will be nitpicked to the very last little detail. That's why it can be so important to make sure we fully understand what laws we're looking at and interacting with when we do things like make these reports or sling around serious accusations. Regardless of your stance on the matter, you must be educated if you're going to involve the legal system in your arguments.