AKUATSU and SOUKOKU HEADCANON:
To keep the alliance between the Port Mafia and Armed Agency stable, Mori and Fukuzawa arranged for Aku and Atsu to be engaged/be partners. Dazai was the one who dropped the idea to Mori in a secret anonymous letter, so he pretends during the meeting he “hears it for the first time” when it is brought up, Dazai shows his full out support to this (Dazai u manipulative little shit). Fukuzawa goes along with it surprisingly.
When Aku and Atsu find out…..eh I’ll leave it to your imagination.
Fukuzawa and Mori also arrange Dazai’s and Chuuya’s engagement behind their backs to even further stabilize the alliance. You can only imagine Dazai’s surprise and Chuuya’s reaction (Chuuya would not take it well to say the least)…..
How I would imagine their reactions to finding out would be:
Dazai(muttering): “*wide eyed at a loss for words* This….this wasn’t part of the plan…the tables have turned on me…”
Chuuya: *distressed Chuuya noises* *flips chair over he was sitting in as he stands in a flustered rage* *stalks out of room* I-i need wine…
Aku: “*towards Mori calmly* Is this an order?”
Atsu: W-w-wAIT WHAT!? *distressed cat noises*
Mori: “They took this as well as I thought they would.”