Tosa Inu Temperament. Are Japanese Tosas aggressive?

Tosa Inu Temperament

At the center of every suitable family dog choice, amiable temperamental traits are not negotiable. Typically, most pet owners prefer dog breeds thought to be less aggressive, loyal, playful and easy to get along with multiple pets or kids living in the same household. 

Sadly, the Tosa Inu temperament is not typically as colorful as you would want for your first-time pet ownership. 

On paper and discussion pet forums, the Tosa Inu is actually thought to be aggressive, but this description doesn’t cover the whole story. 

And for anyone looking for a medium to large dog breed, Tosa Inus have an impeccable soft, laid back side that makes them an ideal family pet as long as the puppy Tosa Inu falls in the right caring hands.

Quick Facts About The Tosa Inu

Height: 62 to 82 cm

Weight: 36 to 61 kg

Colors: Black, Fawn, Brindle, Ref

Lifespan: 10 to 12 years

Tosa Inu Dog Breed Temperament 

Typically, the Tosa Inu is said to be aggressive. However, this description does not fully define this dog because he has many other amiable temperamental traits, some of which you will find to be wonderful too. 

So, Are Japanese Tosas aggressive? 

No! The Tosa Inu is not aggressive or dangerous to both humans and other dog breeds. Contrary to popular beliefs about the Japanese Tosa Inu’s quick to aggression, this dog breed is docile or somewhat soft and has an immense loyalty side when handled well and trained properly at a young age.

 But to get a clear picture of this fighting dog, take a look at other temperamental traits of this dog breed:

1. Intelligent

The Tosa Inu is said to have high levels of intelligence, according to the Kennel clubs. The breed can learn a lot of things in a short period and without repetitions. 

He can do many things by himself, and this intelligence makes him be somewhat independent and stubborn at times.

 Many people are fond of this breed because of his intelligence levels, you can train him to do anything you want, and they obey the training if you show them who their boss is.

2. Loyal

Just like any other dog breeds, with the right training at the right age, the Tosa Inu is very loyal to his family, he will obey commands and do as told. And when there is a threat, the Tosa Inu is known to attack to protect his family.

3. Confident

The Tosa Inu is a very confident dog breed, and this is because he was initially bred to be an energetic fighting dog. So he is a fearless protector of his family and pets. 

This breed is willing to attack any form of threat to his family, and he doesn’t trust strangers or animals outside his family. And with inadequate training, Tosa Inu tends to become very aggressive to strangers and other dogs.

4. Gentle

Yes, the Tosa Inu is very gentle, but this is the trait that gets too little attention. 

At times you will find this breed around his family being gentle and sweet and this is the reason why he is also a good family Companion. 

With the right training, this dog becomes a gentle giant devoted to pleasing his family, he can even be patient and gentle with little kids. And a gentle dog is what every family needs.

5. Affectionate

Yes! The Tosa Inu is very affectionate to his family, he at times loves being with his family and being gentle. 

But one thing for sure is that he does not like attention and cuddles because he is a very independent dog breed, he can do just fine on his own. 

He does enjoy some quality time with his family here and there but this doesn’t mean he will completely become miserable without them like other dog breeds. 

6. Friendly

When properly trained and socialized the Tosa Inu can be very friendly to his family and little kids. He will be gentle and problem them from any form of threat. This is the character that defines him as a good family companion and Protection Dog.

7. Lively

The Tosa Inu is not a very lively dog. As said before, he is a very independent dog breed who can do just fine on his own. He would rather be by himself than out playing with the family or other dogs. 

But with early socialization, this behavior can quickly be diminished into oblivion and you end up with a completely changed Japanese mastiff who enjoys cuddles and social family times.

8. Social

The Tosa Inu is aloof with strangers and is not sociable at all. Yes he will love some quality time with his family but his happiness doesn’t depend on that. He is independent and will mostly also do just fine on his own.

9. Energetic

Yes, the Tosa Inu is a medium to large dog breed, but he is not overly active or too energetic. For him to remain healthy and happy he needs regular exercise such as long walks. Even when left alone for long periods of time, the Tosa Inu will do just fine. He will not turn to be naughty or destructive but will rather remain calm.

10. Playful

The Tosa Inu is said to be the best playmate for children. This is because this breed is very patient and gentle when he is around children. 

He will play with them properly and not be aggressive but will instead protect them from any form of danger that might approach them. 

You can go on and do your chores in the house knowing that your kids are safe with this dog.

11. Alert

The Tosa Inu is said to be one of the best watchdogs because he is very sensitive and alert. He will bark and react to anything unusual happening around him.

12. Vocal

The Tosa Inu will bark and haul once he sees something unusual happening around him. Or once he sees a threat. Sometimes he can bark at strangers.

13. Instinctual

The Tosa Inu instincts are very strong, that is why he needs proper training.

Tosa In Behavioral Problems

With poor training, the Tosa Inu can be aggressive and aloof to strangers. He is also very stubborn, independent and strong-willed, this is the character most owners complain about. 

And, if you let him have his way, the Tosa Inu, also commonly known as Tosa-Ken or Japanese Mastiff will certainly want to be the boss of the family pack. 

Japanese Mastiff dogs are pack animals whose nature is to have the most domineering leader to be the alpha dog. 

Thanks to their intelligence, with the right training and early socialization, all these behaviors can be avoided. 

The Tosa Inu is capable of being a very gentle, loyal and affectionate Family Companion when raised well and in the right hands.

History of the Tosa Inu Breed 

The Tosa Inu dog breed is also known as the Tosa-Ken is, a breed that has origins in Japan and is said to be the largest of all Japanese dog breeds. 

This dog is not a pure breed but was the result of cross-breeding different types of breeds such as the Kochies, Bulldogs, Bull Terriers, Great Danes and Saint Bernards.

 These cross breedings took place between 1868 and 1912. The name Tosa Inu comes from the place where this dog was raised which is in the island of Shikoku, where the city of Tosa is situated.

The Tosa Inu was originally bred to be a fighting dog and the cross-breeding of the different types of dogs finally created an excellent fighting dog with all the skills required of a good fighter, stronger, muscular, fearless and unbeatable.

The dog was finally and officially recognized by the F.C.U in 1982 and he is very rare in other countries. 

The Tosa Inu is the only dog breed which is still used as a fighting dog legally under strict rules and regulations. 

Any dog used to fight the Tosa Inu should not be cruel or bloody and the fight Should not end in the death of another dog.

 The fights are designed to last longer and the breed that goes for fast victory is not considered to be a good specimen.

Tosa Inu Training requirements in Line with His Temperaments

As stipulated earlier on, the Tosa Inu is a very stubborn, strong-willed and independent dog breed who needs early training and socialization for him to behave in his best manners possible.

Use Positive Reinforcements

Unlike other dog breeds, the Tosa Inu will not do well with harsh strict, training. 

Instead, the use of positive Reinforcement will do for him. Praise him when he does according to your commands. 

Reward him with his favorite treats once he does something good. By doing so, you help him to know what is acceptable and what is not acceptable.

Benefits and Impacts of early socialization

You must begin training the Tosa Inu when he’s just a small puppy, your friends and family Should know him while he’s still a puppy so that he grows up knowing that it’s okay to be around strangers. 

The Tosa Inu are naturally born leaders and to be the alpha dog in his pack, so you need to be assertive enough and show a dominant presence in your dog’s life. Be acquainted with the right latest training methods.

House and Potty Training.

Potty training your Tosa Inu puppy is one of the first and most important steps a dog owner can take to prepare for a happy, healthy co-existence with his dog. 

We advise that you do proper research in advance and make sure you have a plan on how you’ll train your dog daily when still a puppy. 

And remember, house training your puppy is about consistency, patience, and positive reinforcement. 

The goal is to instill good habits and build a loving bond with your pet. It will take 5 to 5 months for your Tosa Inu Puppy to be fully house trained because of his natural intelligence. 

And for many new pet owners, consider how much work you will have to put in to train and condition your puppy Tosa Inu long before you buy one. While the cost of purchasing a puppy Japanese Mastiff may not be that dear, there is more to owning a pet than the buying price.

How Much Does A Tosa Inu Puppy Dog Cost?

$1750.00 to $2000.00 is the average price for buying a healthy Tosa Inu female puppy dog. However, if you are going to part ways with your hard-earned dollars of anywhere between $1750.00 – $2000.00, you want to make sure that you are buying from a trusted Japanese dog breeder.

The Tosa Inu is a very rare dog breed in other countries but is available in Japan. 

So if you’re interested in this breed and want to own him, the best place you can find him is with the Kennel Clubs.

 In the pet stores, it’s rare to find him, but you can check, and if lucky, you can as well find him.


Hey, I’m Eddie, one of the publishers at Japanese Dog Breed Guides. And from an early age, dogs have been a massive part of my life. I remember the day my family brought home a Shiba Inu puppy dog, and we called him Ginger. It was love at first sight, no wonder I’m always partially gravitating towards Japanese dog breed. Growing up around a dog breed like the Shiba Inu opened up a new window into this rare dog breed of Japanese Origin. And you would think that having been through with more than one of them, I would lose interest. Strangely enough, my passion for these blue-eyed dogs has exponentially grown from strength to strength! The magic of owning a pet dog is the unconditional love they exhibit towards their owners. And the Japanese dog breeds are no different at sharing that love, which is something special. They’ll always be a part of my life and I hope yours too.

Recent Posts