The core of the shiba is intelligence. The shiba is not to be taken lightly. They are a tough breed, requires ongoing training, communication and care.
If you study the Japanese dog, in general, you will find that the majority of the breeds -- 7 or 8 cannot be domesticated and one of the breeds is the most dangerous fighting dog in the world. The Japanese dogs are extremely intelligent and very willful. They will ultimately do what they want to do. They have a wolf's brain so they listen as long as it provides something or them; e.g. the quality of treat. When you have a shiba, you must calculate your relationship, how you plan to maintain leadership, how to manage your relationship with the shiba and how you will handle issues.
Take a moment to learn about the other dog types in Japan. You will see some similarities in the all of the breeds: intelligence, strength of will, arrogance and beauty.
The Importance of Training.
Training and ongoing training is a must along with consistent practice. Each shiba, no matter how nice it may appear, has a quirky personality and could exhibit some level of aggression. Essentially, aggression is a personality trait. You cannot cure aggression, you can only CONTROL aggression. How will this manifest with a shiba? With visitors, perhaps, with other dogs, seeing lights in the distance and needing to warn you, with anything with wheels (trucks, bikes, etc).
You must take the time through training to know your shiba and identify its personality traits. Then you will know what training you will need to continue with to deal with your dog's quirkiness. My dog, Meggie, for example, is very aroused when she goes out and jumps and barks -- but the irony is, she is actually quite afraid and will never attack. So, the training I use is to teach her to "look" (at me), in order to distract her from what is frightening her. Or, if I can see a situation that could potentially arouse her, I start reminding her to "leave it, Meggie" in advance or I turn her in another direction to distract her. Sometimes, I ask her to sit and I ask her to focus on me while I provide a few treats -- all while the offending source walks past us and leaves our sphere. And I use a series of great treats. You should keep your Shiba guessing. It is part of the fun in training. Also, with Seymour, I could determine what situations would cause him to attack, for example, and I avoided putting him those situations.
You must respect your Shiba. That means, take care of them in all ways; but always make it clear that you are the boss. Never hit them. They remember. Always respect them.
Because of their intelligence they can be somewhat emotionally complex. They get moody when the barometric pressure drops (before a storm) which could go back to their ancient instincts. They respond by being quiet, perhaps hiding, by biting as a way of saying "I need to be alone." or "Leave me alone." The Shiba is "mouthy" and people mis-understand this as biting. When or if your Shiba seems to bite, it may be trying to communicate with you. Do not punish but get to know your Shiba so that they are not put in a position to use their mouth to communicate.
Communicate with your Shiba.
The shiba, it is thought, may have some new guinea singing dog in them. If you really take the time to get to know them, they will start to communicate with you with all sorts of sounds, grumbles, barks, trills. The worst is the shiba scream which is bloodcurdling. Seymour used to sing when he slept.
The shiba has known medical problems: epilepsy, hip displasia; problems with their knees; arthritis; ear infections; cateracts and glaucoma and allergies. You must be willing and able to provide daily (twice a day) ear and eye drops, medicine and in some cases, regular baths if they have skin issues. If your dog has fear aggression you may have to muzzle them on a daily basis in order to provide their ear and eye drops. You must also clear their ears weekly. This is a high-maintenance dog and not for everyone.
The shiba is quite clean and fastidious. They always spend alot of time cleaning themselves. They are very self-focussed and it is important to them to look good. With that in mind, it is funny to see them understand their other end (if you know what I mean). The first time they fart is hysterical. The first time Seymour got constipated, he started screaming on 10th street in Greenwich Village and someone called the police. The people in the apartment thought I was murdering him. I was ribbed by the police for 3 years after that.
Sense of Humor.
With this intelligence comes a large sense of humour. They will provide you with hours of funny stories. I live in a 4-story walk-up. My dogs have been taught to stop at each landing, take a treat (sit) and then go to the next landing. They sometimes would all 3 run down to the lobby, and then run up to the 4th floor again, run to the landing, etc. They are nutty. Meggie loves to jump off of the couch and slide on the floor. They are just funny. I know someone with 2 shibas that figured out how to open the refrigerator and the would help themselves to a night-time treat until he figured out what was going on.
Seymour, my eldest, used to laugh. Something like a snort. He would pull a job on me and then snort. I really loved that about him.