Manatsu No Yoru No Inmu (“A Midsummer Night’s Ithyphallic Dream”) [English, parts 1-2, the story is complete], by Kuroiwa Menou
“Ithyphallic: Of or pertaining to the erect phallus that was carried in bacchic processions. Of or pertaining to an upward pointing, erect penis. (by extension) lascivious or obscene.”
There, now the question about what tf the title of this manga meant can be put out of the way
In this story, two young women bike their way across the countryside, and as soon as they get lost the inevitable tropes catch up, they bathe in a suspicious pond and find shelter in a strange village not present on any map ¯\_(ツ)_/¯
It’s strange, usually I like my manga convincing, but when this futanari, the less explained it is, the better. I really, really could have done without the “biological” explanation about why the two women became horny futas overnight, eager to have plenty of sex, ugh, disgusting
Still, this is very well drawn, girls with realistic athletic bodies, with only very little censorship, so if you’re into futa, check that one out?
Thanks to Q91 for the scanlation!
Fore MORE, cf. The list of ALL Kuroiwa Menou’s Works on Hentairules!
And now, the download & gallery links 
Open the Complete Pictures Gallery
Download the Free Hentai Manga in a Zip file
(21 MB, 36 pictures, English)
Or you can also use the Alternative:
Zip Mirror #1 – or – Zip Mirror #2
… I need say no more.
You get a dick, she gets a dick, everyone gets a dick!