Overview
The 9th Agency is the organization in charge of the intelligence network of DisCity, reporting directly to Paradeisos. It was founded sometime after the appearance of BR-001. (7-2) The current director of the 9th Agency is Langley, who commands great loyalty from the subordinates under her command, as they still report directly to her even after she is placed under MBCC custody (source: Langley's arrest records).
9th Agency agents tend to appear from the shadows in trenchcoats and sunglasses, and are described as spiders in a web woven around DisCity. They appear to have a lot of leeway in the methods they use to execute their operations, including but not limited to spying and torture. They also appear to be aware of many secrets in the city-state, and are the watchdogs that execute commands from the authorities in Paradeisos, although it is not clear the extent of their secret information. For example, Langley is familiar with the existence of the Underground and the Hush system, but was not given clearance to learn the truth about the Hush's role in causing BR-002.
Known activities of 9th Agency include wiretapping persons of interest, assassination of unstable elements and terrorist suspects (Chapter 8, Langley firing on Parma from a helicopter), hacking and manipulating cellphone signals to achieve their goals (Dreamy Bubble event, to divert Doyle away), and purging corrupt elements from the city council (Demon's interrogation). The 9th Agency keeps tabs on other official organizations, and has an "eavesdropper" in the FAC. (7-12) Although the Outland Affairs Bureau is responsible for managing relations with foreign states, the 9th Agency is involved in counter-espionage and thus keeps close tabs on Outlanders' activities. They are also heavily involved in Paradeisos' ongoing war with the Underground, primarily by uncovering Underground agents like Parma, their tools (such as The Garden), and compromised individuals within DisCity's institutions.
The MBCC is transferred under the jurisdiction of 9th Agency at the end of Chapter 8, making the Chief technically a junior agent of 9th Agency after that. It is described in Langley's profile that 9th Agency does not have as many personnel as the other state organizations of DisCity, and it is possible to speculate that agents of 9th Agency may have more than one role in other organizations, just as the Chief is also concurrently head of the MBCC.