Synopsis
Joshu Kasei served for years as Chief of the Public Safety Bureau, overseeing every department including the Criminal Investigation Department — yet "she" is, in truth, an android body used by the Sibyl System itself to move and act among ordinary citizens. Multiple duplicate bodies exist, allowing the identity to continue seamlessly even if one is destroyed, and the personality inhabiting the shell shifts depending on which of Sibyl's constituent minds is in control at any given time.
Kasei presents as cool, secretive, and thoroughly devoted to her work, sharing information with only a select few and displaying unusual personal interest in Shogo Makishima because of his rare criminal asymptomatic status. Akane Tsunemori and Mika Shimotsuki are the only two Inspectors who ever learn the truth of what Kasei really is, a revelation that reshapes how each of them relates to the chain of command she represents.
After an apparent public death, Kasei is formally succeeded as Bureau Chief, though the Sibyl System continues to make use of the android identity when circumstances require it.
