It's always the governments

Because Dazai's informant in the Hero Public Safety Commission (HPSC) found a file stating, that Japan's government is planning to mess with Yokohama, and Chuuya heard rumors about All for One planning on taking their city over, the ADA and the Port Mafia agreed on sending several of their members to deal with the outsiders. Since the peace of Yokohama (If you can even call it peace) and the safety of the ability users depends on the success of this mission, the detectives and mafioso are going to infiltrate following places/organizations: Kenji, Kyouka and Q are going to Yuuei, Tachihara and Gin will infiltrate the League of Villains, and last but not least will Chuuya and Dazai search jobs in the HPSC.

For the sake of all of them getting recent updated on the others, Akutagawa Ryuunosuke and Nakajima Atsushi will be transferring information and spy after them in big crowds, additionally will Ranpo give them different strategies and Tanizaki is going to be on backup if someone important gets in serious trouble.