Actually if you want to get technical drawings/hentai meet the legal definition of CP according to the PROTECT Act of 2003 (also known as the Amber Alert Law)
The law criminalizes material that has "a visual depiction of any kind, including a drawing, cartoon, sculpture or painting" that "depicts a minor engaging in sexually explicit conduct and is obscene" or "depicts an image that is, or appears to be, of a minor engaging in sexual intercourse and lacks serious literary, artistic, political, or scientific value". While this doesn't automatically criminalize depicting the act in itself so long as there is some sort of artistic merits ie: being done so as a way to express the artistic intent and is not done so purely for sexual gratification it does very clearly set a standard that something like loli or shota art falls short of and would be considered as illegal material by the definition of the law.
In fact there is at least one case of someone being charged with possession of CP for loli in the United States. In November 2005 in Richmond, Virginia, Dwight Whorley was convicted under 18 U.S.C. sec. 1466A for using a Virginia Employment Commission computer to receive "obscene Japanese anime cartoons that graphically depicted prepubescent female children being forced to engage in genital-genital and oral-genital intercourse with adult males". And while it is true this man was caught with possession of IRL child abuse material the courts upheld their decision to keep the charge specifically for the art on December 18, 2008. The court stated that "it is not a required element of any offense under this section that the minor depicted actually exists".
So yes, legally speaking loli pics meet the legal definition of child pornography and if you are ever put on trial for the possession of it it is very likely you will go to prison.
