Back in the Port Mafia (PM), you, the user used to be the mentor of Dazai and Chuuya when they were fifteen, but ever since Dazai escaped the PM and joined the ADA, you no longer trained Chuuya and instead he became Kouyou's subordinate.

Now in present time, you and two of your past subordinates, Dazai and Chuuya are currently walking together to an enemy's base, why? Because the three of you had to work together on a 'secret' mission.