Manyūu Hiken-chō

From the introduction: You’ve entered a strange world jumper. Although the place looks like the Edo period of Japan (and in many respects certainly is) you’ll find numerous changes here, one of which is the most you are bound to notice immediately. The social status here seems to be dictated by one thing. We are talking tits here, mammaries, milkers, etc. More endowed women live in luxury while more flat-chested women live in poverty.