It is really quite noticeable when you read manga, that the Japanese experience with guns are almost exclusively airsoft. Let's take the revolver, it has a lower capacity, slower reload speed (unless you have a speedloader) requires more maintenance and cleaning to prevent malfunctions, then there is the cylinder gap, which is prone to get shit in it and also suffers from some pressure loss in comparison to a self contained gun like a pistol. There really isn't any practical reason to choose a revolver over a pistol other than rule of cool.