For ghouls, the ward is nearly uninhabitable.
In the past, Eto excuted a large-scale attack on CCG's 2nd ward branch office. The office was heavily damaged and CCG suffered numerous casualties. Later, Eto's faction attacked the 2nd ward for a second time. Yoshimura, acting in his daughter's place, attacked the 2nd ward for a third time alone. CCG's team was unable to exterminate Yoshimura. However, the genius Rank 2 Investigator Arima used the Special Class Investigators' quinques as he went up against Yoshimura. Finally, he defeated Yoshimura, leading to CCG's victory. Yoshimura, wounded, vanished after this day ten years prior to the Aogiri Arc.