Reincarnated as the only male in a futa world, where you lose your rank if you are impregnated. And no one believes that you cannot get pregnant.

The protagonist is reborn in a fantasy world where disputes are settled by sex fights. With rivals fucking each other until a spell reveals that one of them is pregnant.

This protagonist repeatedly insists that he cannot get pregnant. But literally no one in the story believes him. And they all insist he is just bluffing.

As their creator goddess ensured that all things that live and breath can bear children in this fantasy world. No one believes other wise. Despite any evidence to the contrary.

The protagonist is forced to take part in multiple sex contests. That by definition he cannot lose.

But each challenger is absolutely certain. That they will be the one to pound his butt till he gets pregnant. And they each think that he's merely an tougher opponent than most. And their victory over him will be all the better once they do make him pregnant.

This misunderstanding is partially caused by the presence of lizard girl futa's in the setting with cloaca's. Who were long ago believed to not be fuckable. Till a legendary heroine fucked the lizard queen into submission. Thereby securing the safety of the human realms.

No matter how many times the protagonist tries to explain, in thorough detail, how he comes from another world where men exist. And men born with an XY chromosme cannot get pregnant. The people of this realm refuse to believe it.

They challenge him to sex fights. Fully believing in their heart of hearts. That they can get his bussy pregnant before he can impregnate them. Puting their rank, their honor, and their womb on the line. In their search for glory.

As they all want to be the first woman to breed this new adventurer from another world.

Where there is a hole. There is a goal. And their goal is lofty indeed.