The Hong Kong Kowloon Treasure Murder Case File 2 - S1-E2
Plot hole: An essential part of the plot relies on the fact that thanks to Saki's handheld camera, Kindaichi can examine Ran's arse dragon and therefore investigate even in her absence. But what set the plot in motion was the fact that Ran appeared in a professional modelling photoshoot displaying it. Stupidity of the girl aside, that means that the culprit never needed the girl, having HQ shots of the tattoo at their disposal. They even work for the company.