Teguri Yoseru Amai Yuuwaku (“The Sweet Temptation That Beckons”) [English], by 3104
There’s also the mangaka using the “212” pen name, to me it’s always weird, choosing to be named after numbers. There must be some form of fun or private joke which we will never know…
Ahem, sorry. Here’s a niche story, based on netori and moral corruption (a highschool girl is unsatisfied with her loving but lacking virility boyfriend, just then the local scumbag shows up, he treats her like shit and fucks her like a sex god, she’s in heaven ), I can’t recommend it to everyone.
To make it worse, there’s this gross blur mosaics I hate so much.
And yet, see, I’m sharing it. Because after all, within its own niche, I felt the story was well delivered, if you dig this kind of thing you should enjoy it a lot. And, in terms of art, oh boy, the girl’s body, her positions during sex, her facial expressions, that was awesomely drawn
This is a Nisor release, thank you!
By the same artist, with a variation in the name: 3104Tyome, I also share Soon Lazy.
And now, the download & gallery links 
Open the Complete Pictures Gallery
Download the Free Hentai Manga in a Zip file
(33 MB, 25 pictures, English)
Or you can also use the Alternative:
Zip Mirror #1 – or – Zip Mirror #2 – or – Zip Mirror #3
Most of the time the number are an actual name (kinda like the main character from Darling in the Franxx). Depenfing how you look at 3104 could actually mean the name “Sanichi Marushi (3104)” or “Sanjuuichi Marush(31,04).”
I could be wrong, but I usually figured that was the case?
One clear advantage that should be obvious in any language is that alphabetical sorting puts numbers before letters, so this author will come up before any name beginning with a letter. Seems crazy to me, but who knows.
Decent crunchy frog.
This scumbag has talent. Not many people could take such perfect blackmail photos when they have no eyes.
The variation is because “3104tyome” is the circle name, while “3104” is the artist’s pen name.