Otaku In 10,000 B.C. vol. 1, the (18+ manga) 10000

Even though this story is from the past, things like big breasted milfs are timeless! FAKKU is back with a prehistoric tale that was almost lost to time, The Otaku in 10,000 B.C. by Nagashima Chousuke!

Our first Isekai release is centered around a hopeless otaku named Ota. Unlucky at love and with nothing going his way, Ota’s world is turned over when he’s magically transported into a land that time forgot. Surrounded by nurturing, big breasted cave women with seductive banging bodies, Ota’s going to have his hands full teaching them a bunch of firsts in the history of sex!