Similarities:

•second chance romance
•mature leads
•the coloring and feel of the filming
•great chemistry between leads

Something about the feel of both shows seems similar. Melodramatic and the coloring of everything. Mature leads and has a lot of thrilling situations.

Similarities:

The main leads fall in love (though Hello Monster has less romance I believe and they don’t get together until the very end)
More serious male lead in both
Smart female lead in both
Different cases get worked on but there is also one main big case leading up through the series
The chemistry is better for the main leads in WASFIL I believe.
Both are very enjoyable to watch ?

Very similar in the way the leads falls in love and they work on cases together. The leads also have great chemistry!

Something about this gives me the same feeling as Doom at your Service.

-bad boy male lead
-sweet female lead
-beautiful visuals
-chemistry between leads