いもーと特区〜妹と結婚できるいい時代になりました〜

The protagonist, Imose Hiroshi, had been overseas for five years because he fell out of favor with the company's slick manager.
When he finally finishes his duty and returns home, he is greeted by his three beloved sisters.
He decides to fully use the month-long vacation he has received from his company for his sisters, who have been waiting for him...

Meeting them after five years, they have grown up to be attractive girls with abundant fruits. What's more, all of them had developed an increased love for their brother that they had harbored since early childhood!