Dazai and Chuuya have been secretly married since 18. Now, in honor of the truce between their organizations, they make a big show out of messing with their colleagues while subtly, or not-so-subtly, revealing their relationship. Also: They're disgustingly in love.
Or:3 times Soukoku had the time of their lives messing with their co-workers and the one time they finally told them they were married.
One night, Chuuya accidentally activates corruption in his sleep. Fortunately, Dazai is right there to stop him and from then on, a certain arrangement is formed.
Or:An Anti-Arahabaki sleeping arrangement turns into a happy marriage between two idiots in love