Jacqueline de Signore (ジャクリーヌ•ド•シニョレー Jakurīnu do Shinyorē) is a woman who is the wife of the current Superintendent-General of the Sauville Police. She shares a past with Grevil de Blois, who turns out to be the latter's childhood friend and crush.
Before her engagement to Superintendent-General Signore, she was framed for the murder of a veterinarian and this causes Grevil to resort to asking help to his younger sister Victorique, for an unusual price.