Peter Grill and the Philosopher's Time Vol. 9 (manga)

Fame has brought no shortage of women to the World’s Strongest Man, and with a dragon girl named Menma as the latest addition to his harem, Peter decides to buy a mansion for his beautiful entourage to live together in sin. But when his younger sister and fiancée’s father both swing by for a visit, a very naked Peter and his company must scramble to avoid the deadly wrath of two extremely dangerous relatives!