In the second season of Bungou Stray Dogs, a trio of men from different factions, including the Port Mafia's young executive Osamu Dazai, the low-ranking Sakunosuke Oda, and intelligence agent Angou Sakaguchi, unwind at the Lupin Bar each evening. However, when Angou mysteriously vanishes, leaving behind only a photo from their gathering, the past collides with the present as Dazai joins the Armed Detective Agency. With the arrival of the American organization, the Guild, tensions rise as they threaten the Agency's operations. Now, torn between the Guild and their long-standing foes, the Port Mafia, the Agency must navigate this precarious balancing act to protect their very existence.