Wax Doll Castle Murder Case: File 3 - S1-E9
Plot hole: Miyuki is not a detective or has any qualification in the world of crime novel. Her presence (taking up one of the 10 slots of detectives picked from all over the world, she's not an accessory to Kindaichi) is completely unexplained and nobody questions it at all.
Wax Doll Castle Murder Case: File 3 - S1-E9
Plot hole: According to what was established in the first episode of the arc, the statute of limitations for the crime has expired. In this third one though, it is said that they are afraid that the body will be discovered. There's no link between them and the victim (s), so to say that they joined the whole madness because they needed to prevent the castle from being 'moved' is absurd.