Season 1 of Detective K9 premiered on July 5, 2019.

A car accident changed Ray's life completely. After the surgery, her sense of smell improved exceptionally, even better than a dog's sense. She then used this special sense to gain extra money by helping people investigating simple cases. One day, Ray happened to meet and remember a particular smell from a thief's body and so she was invited to join the police detective team by Poom, the inspector who was seeking the most-wanted thief. While working as a spy for the police, Ray meets Q, a famous DJ with a secret.