Ex-Arm: The Novel - Kikaishin

Shin Kagurazaka, a town that escaped the Tokyo Olympic terrorist attacks. From general ikazayas, to sexbot-specialized brothels, or undergound gambling dens, it is regarded as a gigantic entertainment district where one can indulge in their pleasures. In this town, the EX-ARM Countermeasure Division receive reports of a "smuggler," and sends in Alma in an undercover operation. Her target of infiltration is a girl's bar. Meanwhile, Minami encounters a mother who asks for help in finding her daughter.

(Source: Shueisha, translated)