Bishoujo Club

A 2012 Hentai manga created by Akatsuki Myuuto.

Franz is a young boy who lived his entire life sheltered on a house, living only with maid Liese. After manifesting sexual feelings for Liese, Franz is finally taken to outside his house to live on a school where the every other student are girls. However, he must pretend he's a girl to them.

Serialized on Comic Mujin.

Tropes used in Bishoujo Club include:

Adam and Eve Plot: The administration of the school actually don't cares if Franz's secret is discovered and have sex with the girls because of this reason.
Apocalypse How: Class 2, though the girls are taught it was a half Class 3(only the men were extinct).
Babies Ever After: In the end of the story Liese is carrying a baby of Franz.
Blood From the Mouth: How the virus spread by the "Purebloods" work. Yuuya dies bleeding copious amounts of blood from his oral orifice.
Compelling Voice: Later in the story Franz is taught he can use this kind of power over the girls of the Garden using special words. And he fully abuses it.
Crossdresser: Franz pretends to be a girl named Iris to preserve the girls in his school's ignorance of the existence of living men.
Dead All Along: Franz's grandma has passed away sometime ago. Who actually commanded the school was an A.I. following her instructions.
Double Entendre: The garden seems to be named that way because it is where young girls are raised; however, considering the administration's plans, it seems to be a place to "cultivate" babies.
Dude He's Like in A Coma: Franz kisses Liese while she's asleep as result of sleeping pills, or at least is what he thinks; she was actually him tempting to go after her while she's defenseless to test how great are his sexual urges.
Dude Looks Like a Lady: Franz is already very feminine looking, so pretending to be a girl isn't hard to him.
Foregone Conclusion: Chapter 10 is a flashback to how the world was just before the towers of Sephiroth fell down, with the father of the protagonist being one of the "Purebloods". So, the towers exploding and the virus killing the male protagonist isn't a surprise.
In Medias Res: The comic starts with Franz already having an orgy with several girls, so you know who his secret will be discovered. Of course, considering it's a hentai manga, that wasn't exactly surprising.
Open Secret: The administration of the school fully knows that a group of girls know "Garden Iris" is a girl and are having sex with him; in fact, it seems like they wanted it to happen all along, using Forbidden Fruit to make them well more willing to have sex with him than if they knew all along that he was a boy.
Star-Crossed Lovers: Yuuya and Jessica, as he dies from the virus spread by the "Purebloods" not much time after their relationship starts.
Villain Protagonist: Franz turns into this as he abuses his power over the "Garden" girls to have as much sex as he wants with as much of them he can.
Well-Intentioned Extremist: The "Purebloods" destroyed the towers of Sephiroth and spread a killer virus to, in their words, direct the world in a better direction, as mankind was suffering with a decline on sexual drive.
Zettai Ryouiki: Almost omnipresent in the "Garden" students' school uniform.