Only two loli hentai existed in like 2012-13 I think,
It was one with the goth loli from boku wa tomodachi wa and some other one that was kinky.
Back in like 2012 or 13, there was this one loli hentai about a middle aged wife loli selling herself to the husband to buy a brand new laundry machine. She got price tags on her nipples and crotch.
It was like '3000000' yen. I want to read it again so I can see the new laundry machine.
The earliest I could find was from 1/23/2007 [Etoile Zamurai (Gonta, Yuuno)] Suki Suki Elfen Lied (Elfen Lied) their was loli befoe it if you count herminy from harry potter, or saber from fate
I barely seen any loli hentais in 2014 and bellow, and there was bunch of configurations around then such as directly cooperating with authors. Probably hid the loli hentai for a while until they needed to attent a larger demograph of lolicons