If u (by any chance )want to see it's Chinese version then "My Roommate Is a Detective" has the same plot. It's the exact copy of "Secret Royal Inspector".
set in a similar era. the 2 male leads meet each other and they help each other to solve crimes. has a bromance feel towards the 2 male leads. 1 is an actual detective and the other is just a helper/consultant. they gain popularity through the cases they work.
-Similar story setting
-Same thing it is a detective drama
-Has a story line of Crime and investigation.
-if you like this dramas then this the truth is another option.
-Both are Detective Dramas
-Solving crimes and figuring out who is the culprit.