i'm looking for mystery (or even thriller) dramas that have a good friendship/bro/sismance/found family element to them. any country is fine! thank you 

The only title that popped in my mind now is Psych-Hunter. The bromance in this is pretty good, and they have a case by case mystery to solve :)

Hello Harinezumi - mystery comedy with great bromance of main detectives

Please do yourself a favor and watch Murderous Affair in Horizon Tower if this is your thing. Unbeatable for me in this aspect

You're All Surrounded- I really liked the way the team worked together in this one they really do become like a found family by the end of the drama

Trick- the dynamic between the main characters is great here. The magician, the professor, and the cops really play well off of each other

Vampire Prosecutor- It's been a while since I watched this one but I remember liking the team dynamic

You can try Again My Life .. Kinda mystery/thriller/action IMO.. The ML befriended almost everyone and their friendship is really good..

Maybe also Stranger (if you haven't watched it).. The leads friendship is really cool I think..

Also  The Good Detective .. the bromance there is noteworthy..