Hoshi no Yakata

From here:
Hoshi no Yakata centers around the employees of a suburban s/m club. The characters are beautiful, the storylines are angsty, and the artwork is horribly explict. What more could you ask for?
Most of the story takes place inside or on the grounds of Hoshi no Yakata, a humongous European-style mansion.
The story’s other locale is Airenrou, another club located a few hours’ drive from Hoshi no Yakata.
Name of the 5 volumes in the series :
1) Hizamazuite Kutsu ni Kiss wo (Kneel Down and Kiss my Boots)
2) Kedamono wa Ori no Naka (A Beast in the Cage)
3) Yokubou no Mitsuryousha (The Poacher of Desire)
4) Toraware Hito no Ikisaki (The Prisoner’s Destination)
5) Doreitachi no Jouken (A Slave’s Condition)