Inspector Koo (2021)

An eccentric former police investigator works insurance cases with a small, unevenly matched team while becoming fascinated by a formidable opponent. Inspector Koo combines comic behaviour, puzzle-solving and a partnership that keeps shifting its balance. Choose the Korean-language series for unconventional people finding a way to investigate together. The serial-killer material and psychological contest make it darker than Only Murders, so treat it as the more unsettling end of the recommendation rather than a cosy equivalent.