Reijoku no Yakata ～Inroku 5shimai Jukanki～  

麗辱の館～淫緑五姉妹汁姦記～

The main character starts working at some house as a live-in janitor. There live attractive five sisters. He is an orphan, so he wants to get everything in front of him. Sisters are confused at first, but they are gradually addicted to it....