娼館のエミリー

Four years and two months ago, a group of sorcerers opened a portal to another world, and thus the war between demons and humans began.  Humanity struggled but is now pushing back hard to reconquer their land.

Behind the scenes prostitutes serve the needs of warriors with the use of new technology allowing lolis to rapidly develop. Main character is a mercenary who opens a door and sees such a prostitute asking for shelter.