Yanagiba Hiroki is your average guy working in retail. He goes hiking, aiming to make a video about a local legend of onis living on the mountain. Somehow, he strikes gold: he stumbles into thick mist and reemerges into a village populated by oni. Then comes a twist: the village is populated solely by oni women, with all the men having died in an epidemic decades ago. The village chieftain proclaims that he is to stay in the village until he manages to impregnate at least five women. But as horny as they are, oni women are not that fertile, meaning that he’s in for months of non-stop baby making sex with a whole village of hot oni ladies~

Oni come in various shapes and sizes, from a giantess to a shortstack, from a mature older lady to an exceptionally horny bisexual flatty. And poor Hiroki has to creampie them multiple times every day until he runs dry. What a terrible fate...