HEY THIS IS SUCH A NICE QUESTION WAIT

so idk but based on appearance you’d expect the both of them to be stoic but i think they both know the appropriate time to joke around when the atmosphere gets too serious (this is for irl kuma). but if we’re talking about fictional buddy cop dynamics i totally see fuma being the comic relief or boke while kei would be the serious tsukkomi who just wants to get things over and done with at a reasonable pace 😭😭 like they’d be investigating a crime scene with a missing victim and suspect and kei’s grabs a bloody bread knife like.. wow So this is the murder weapon.. then fuma swoops in like heol yabai Do u think our victim was the sourdough on the counter..

BUT LIKE i think fuma would give ranpo + dazai vibes (do u know them anon.. from bungo stray dogs) like he would do a little jokey joke BUT in a pinch he’s like super OP and reliable?? and he would be the fan favorite methinks

and it would be nice if kei were someone like megumi/nanami (jujutsu kaisen) Where he has a cold (looking) exterior and gets the job done but he’s really a softie inside who values efficiency
:D

thanks for the really nice question!!