For Japanese dramas: Goritekini Arienai: Tantei Kamizuru Ryoko no Kaimei Enjiya Galileo - this one has multiple sequels (dramas and movies) which are all great, though I do think s1 and Midsummer movie are the best. The ML is a university professor, so from his persona a bit more different to the ML from Flex Cop. Plus this drama has some very well developed cases. However it fits with Flex cop due to the ML not being police, the chemistry between the leads and the humour.