This is the a playback special called the Tokyo Investigation SP. The past clips played included less visited Tokyo 23 wards ranking (Ep. 359), Edogawa Ward problems (Ep. 294), Toshima Ward population decline (Ep. 293), Kitasenju-Minamisenju dispute (Ep. 291), a map of Tokyo rail lines in literally translated English (Ep. 393), uncommon songs for town (Ep. 359 and 393), the least popular park in Tokyo (Ep. 359), and the tragic cafe near Takanawa Gateway (Ep. 393). After that they also showed railway lines investigation from episode 239, 251, and 257. (Source: Griffin Seannery at MyDramaList)