Yes, I am aware of the pre-serialization where Agawa gets creampied and mind broken by the fat teacher.
I am referring to this version here, which was supposed to be the "plotsy" version without the hentai.
From the looks of it, the author got bored of the plot and wants to go back to the hentai version.
The hentai version hasnt been fully translated, but that is not what happens in it.
Spoilers i guess, but it has a pretty wholesome ending, they fuck at school, they get exposed, expelled from school, separated from eachother, then reunite and live together as adults.
At the end of the hentai the author drew a couple of pages showing what i assume are previous hookups, including one with the ugly bastard teacher. Im pretty sure that these pages are from before the hentai happens because after the hentai agawa has longer hair, so it wouldnt make much sense for the teacher bit to happen during or after the hentai takes place.