My takes on some ploy ships involving Dazai and Ranpo
Kunichuranzai this Kunichuranzai that but . . . what about . . . Mushiranpoezai!
I don't normally ship ships with 3+ people but I thought of this. Alternatively there's Mushiango and just Ranpoezai.
IDK how Poe would feel about Dazai though. I think he'd feel okay if Ranpo liked him, but their personalities don't seem that compatible (they even are different types of morbid). And I feel like Mushitarou would be low-key terrified of Dazai (that or weirded out). Just my opinions though.
And I personally see Mushitarou feeling at first very intimidated and then as they become friendlier, affectionate, but platonically towards Ranpoe, so I ship him more with Ango.
I propose Mushiranpoezai because I feel like kunikidazai and souheki have such different vibes (more soft and domestic and pure) than soukoku so they wouldn't really all get along. Also because of the conflict with Chuuya being a literal active criminal and Kuni's ideals, and Ranpo's connections to the police.
Chuuya is so free. He wants to live life to the fullest to prove he's human, which I think could clash with Kuni's need for organisation. On the other hand, he's an extremely hard and dedicated worker (workaholic) and cares about people to value their schedules.
I think Ranpo's brutal straight forwardness could be good for Chuuya's trust issues, but I see Chuuya having a hard time getting over his rudeness (despite his swearing, Chuuya is still a very considerate person, like when he walked that lady across the street in wan). I think Chuuya would find Ranpo insufferable and spoiled and probably be very annoyed by him, maybe because he might view Ranpo as having a much more luxurious childhood than him.
It's true that Kunikidazai and SKK are similar dynamics, but not nearly the same, their banters are motivated by very different things and one carries way more negativity than the other and probably more dependance (at least on Dazai's part).
So while I like all these ships individually, and I don't really ship either poly ship, I personally believe based on my interpration of canon and the characters that Mushiranpoezai is more plausible.