HELLO DEAREST ! !! !
this is hard... i don't even know what i can concretely consider my otp... probably odazai though. so
hmm... i'm really fixated with oda having a monster cock. like 100%. i mean that's basically canon, right?
besides that, something less perverted, is that oda is the ideal house husband! i'll extrapolate more below ~ but
cw for references to eating disorders !

in a domestic setting, dazai really struggles to eat properly/get enough nutrition. he's a really picky eater and canned crab is like. a comfort food. but obviously a complete diet it does not make!
oda accepts this about him and doesn't try to push him to eat more, but he's still worried about dazai. he makes a lot of effort to prepare him foods and try out different things to ease him into a more well-rounded/nutritionally complete diet.
dazai is a terrible cook, and really hates doing it. but slowly, he learns to enjoy it from time to time with oda, especially when they do fun things like make sweets together.

i think that's interesting that poe doesn't like sweet things... what kind of food does poe like then?