The Slave Ship.

Onimata Kan is famous for two things: a successful career writing S&M erotica, and hosting the erotic gatherings aboard what has come to be known as the Slave Ship, where the main attraction is the auctioning of the services of sexual partners willing to fulfill any desire. So if it's all consensual, there's no harm, right? At least, that's what Onimata believes until he learns that one of the frequent auctionees has gone insane, and that her husband believes the cause is related to a stalker she acquired. Are the activities aboard the Slave Ship somehow to blame? Fearing the answer, Onimata goes to investigate the mysterious Kitagawa, and soon learns that his own writings only hint at the extremes to which some will go.