Creature Girls: A Hands-On Field Journal in Another World Vol. 13 (manga)

FORBIDDEN SCIENCE AND FORBIDDEN DESIRES!

Much to Daisuke's amazement, a pair of genuine, pointy-eared elves have arrived at the Ra Clan village. The two of them are mother and daughter, and they hope to obtain some of Daisuke's otherworldly scientific knowledge. High elves like them are the product of countless generations of carefully-managed breeding, a program designed to produce immensely intelligent minds. But in a world where technology has been mysteriously suppressed, there are still many questions even living computers like them can't hope to answer. In a private meeting with Daisuke, they reveal shocking truths about their world...and soon after, they give him an erotic experience he'll never forget!