Onnuri Seongmunhwa Yeonguso

In the year 2040, mankind developed a time machine that could move through time and space to the past. So what are you going to do with this machine? “Research the (obscene) times when sexual culture bloomed!” …With this aspiration, some extraordinary perverts- No, researchers, gathered in the Onuri Sexual Culture Laboratory. From her on, the interesting human sex research begins!
(Source: Lezhin, translated)