As a Shiba Inu, Marou can be very aggressive when excited or startled, which can be fun for people who like to be rough with their dogs or to train them as guard dogs.
The Shiba Inu is not the kind of dog i would care to make into a guard dog, though i do like to do a little rough housing with him from time to time as a reward for good behavior or using the potty outside.
I have to be very careful so as to not get hurt badly or hurt marou in the process, as he is a little guy and he bounces very well.
Josie and I have been pretty diligent about teaching him to calm down when we accidentally get him a little too excited. It's always helpful to have a 'safe command' (to make the dog stop/sit down or lay down) for rough play just in case your pet gets a little too aggressive, especially in larger canines.