Responses
This is like an alternative present or future where the red-light district has revived in Japan...I think ╮( ̄▽ ̄)╭
This^^ It's explained in the beginning but it's not super clear.
http://www.mangago.me/read-manga/mede_shireru_yoru_no_junjou/mf/v01/c001.1/13/
I cannot figure out the time period. The clothes, buildings, photographs, cars and other stuff don't match up with the 17th century dates, plus he mentioned blood types which they wouldn't have known back then.