Monzetsu

A Hentai Manga series by John K. Peta, mostly about women (who are made of rubber) being raped. Most entries in the series have been anthologies with no overarching theme, with the exception of Monzetsu Explosion, which is about a, um, full-service cafe. Remarkable mostly due to the nice art and graphic subject matter.

Tropes used in Monzetsu include:

Anatomically-Impossible Sex: And how!
Biggus Dickus: Most male characters (in cases of more realistically proportioned guys, the story makes up for it by providing a lot of them).
Brother-Sister Incest: While not the main theme, it does show up every once in awhile.
But Liquor Is Quicker: Sometimes, even self-inflicted.
Camping a Crapper: Many encounters take place here, many of them non-consensual.
Christmas Cake: While most of the female victims are schoolgirls, a few teachers and "older sister" types get in on the action from time to time.
IKEA Erotica: Take a shot every time a girl yells something about a specific internal organ or component of her uterine structure.
Karma Houdini: Many of the guys get nothing worse than exhaustion/dehydration for their crimes.
Karmic Death: Then again, some of them get seven-week-old rancid milk.
Lampshade Hanging: A common cry from the females is something along the lines of "No! That's impossible! You can't fit X that far into my Y!"
My Girl Is a Slut: Boy howdy. One of the anthologies opens with a story about a girl's boyfriend discovering she has another boyfriend, and after they, um, ally against her, a third boyfriend appears, and so on...
Naughty Tentacles: Mostly relegated to Omakes in the last few pages.
Nerds Are Sexy: The Chemistry Club Leader.
No Periods, Period: Every so often a girl will reference where in her cycle she's in (of course, it's exclusively "safe days" or "I'm ovulating!")
- Not exclusively. There've been a couple where the forced impregnation threat was part of the plot and a handful of ones where unconventional methods of birth control are practiced ranging from forcing the girl to suck the sperm back out to pinching closed the fallopian tubes. As noticed below, yes, they fail biology forever.
Pizza Boy Special Delivery: It's implied a housewife was raped by, amongst others, a paperboy and a mail man in one story.
Potty Failure: Type #1 with great frequency, Type #2 on occasion.
Rape Tropes: A great deal of them.
- Rape Is OK When It Is Female On Male: Notable in that the first story in the first anthology of the series is about a schoolgirl raping her teacher. Sorta like Mood Whiplash really.
Rule 36
STD Immunity: More like pregnancy immunity, really. So far there's been one actual pregnancy, which is really weird considering what the stories are about.
Vomit Indiscretion Shot: Often a result of Biggus Dickus, or even more twisted acts.
Artistic License Biology: Anatomy does NOT work that way, ladies and gentlemen! Good night!
You Suck: A few of the more detestable male characters are implied to be much the sort of person who reads the series.