Courtesan is a profession as old as time and the Yamagawa clan is certainly old. Nobody really knows how or when the Yamagawa's first appeared in the Hive, but their reputation is widely recognised at all levels of the Spire, even in its dark, dank depth. Whilst they don't carry the same sway as other houses of the Spire their positioning in high and low society, and the rumours that surround their house, make them one to be feared and cautious, even by close colleagues and friends. They are a family steeped in tradition and superstition, and are led by their aged matriarch Torii Yamagawa. She is a friendly and kind seeming woman, but a ruthless and powerful woman to end up on the wrong side of. Her Yokaisama are masked warriors, highly skilled in silent, lethal and precise forms combat. They wear long coats and skull masks giving them a fearsome, supernatural presence.

Her profession and that of the family, during its long history, is that of raising, training and providing courtesans across Necromunda to a wide clientele. Each courtesan is precious to Grandmama Torii, and their lives are dedicated to her and their work. Whether this has anything to do with her kindness to the destitute of Necromunda or the rituals she makes them enact upon completion of their training, their dedication to the Yamagawa clan is important because as well as being courtesans to some of Necromunda's wealthiest (and least wealthiest it must be said) they also supply, distribute and manipulate the spreading and suppression of secrets and information, the real profession of the Yamagawa family.

Scrap Bank is no different to the high Spires when it comes to people looking for companionship. Whilst small, Yamagawa's agents still work their profession here and the Scrap Bank is a hot-bed when trade is concerned. Its numerous dockyards make it a hub in the sump for visitors, tradesmen and more clandestine figures to congregate and sell their wares, a location ripe for business, and for spreading the reputation of the Yokaisama's ways and for Torii Yamagawa to further her family's ultimate secret.