Reijoku no Yakata / House of 5 Lusts

Shun is definitely an orphan working in a mansion owned by a noble group of five voluptuous, wealthy sisters. To acheive his on the job the fortune, Shun must insert himself into the family's politics and many types of five sisters! But it looks like these virtuous high-class women are typical beyond his league. Then Shun learns the secret desires of Tsubame, the second sister plus a well-known novelist. With her body and help, Shun is preparing to drive down his fleshy path to riches.