Shunjou Oni Musume (“Lusty Oni Girl”) [English], by Takahashi Takashi
Would you look at that: vanilla hentai with a female oni, it’s rare, it’s drawn with a unique, pleasant and original style, and it’s heart-warming =)
In Shunjou Oni Musume, a male human is somehow transported back in ancient Japan, where the local village folks believe he’s a sorcerer, and task him with getting rid of an oni stealing their food. Not being a bloodthirty barbarian, our XXIst century guy finds the oni is female, sympathizes with her, and basically turns her into a cute horned tsundere. Soon enough, they’re having sex (hey, with only 27 pages, you can’t waste time ^^), etcetera.
The story’s flow was adorable, and the ending, haaaaa, so sweet, so cute
I hope you’ll enjoy reading it as much as I did, so thanks a LOT to Hentai_Doctor!
And now, the download & gallery links 
Open the Complete Pictures Gallery
Download the Free Hentai Manga in a Zip file
(24 MB, 27 pictures, English)
Or you can also use the Alternative:
Zip Mirror #1 – or – Zip Mirror #2 – or – Zip Mirror #3
He should have just told the oni that he’s an isekai character and therefore more overpowered than Popeye at a spinach farm. Every oni in Japan would have dropped dead in terror!
I read stuff like this and start thinking the “gods” are just a group of caretakers making sure that sentient species don’t go extinct.
Like the powers that be pulled this guy into the past to get him to breed with an oni and pulled them back into a more tolerant time to produce offspring to repopulate the oni species.
We’ve gone from international families to inter-dimensional ones…progress.