The Borgia siblings have calculating minds housed in youthful bodies. Although in life Cesare was the influential one while Lucrezia was used for political marriages, Erice Utsumi wonders if truthfully Lucrezia might have secretly puppeted both her brother and their father Pope Alexander VI.
The Borgia siblings are concierges at a hotel in Akihabara, but also secretly serve as Erice Utsumi's information brokers. Their Master is the aging manager of the hotel, but most of the managing is left to them.
The siblings would often require payment in more than money. In the past, Erice had to let slip secrets that she'd learned of the criminal underworld in exchange for their information. More than a few times, it had later come to light that a Servant she had disposed of had been someone they considered an inconvenience.