The Tosa can be called the Japanese Mastiff. Many countries have a clear mastiff breed: the Rottweiler of Germany; the Mastiff of Great Britain; the Dogue de Bordeaux of France; the Napolitan Mastiff of Italy and the St. Bernard of Switzerland etc.
Many Japanese varieties are named after the province in which they originated. The Tosa is the native dog of Tosa-Wan (Tosa Bay), located in the prefecture of Kochi on the southern Japanese island of Shikoku. Although the Tosa we know today has a predominantly mastiff-like appearance, The original Tosa from Tosa-Wan is a spits-descent with a rough coat, upright ears and a tail that curls over the back, similar to the modern Akita and Shiba inu.
Until the nineteenth century, Japanese varieties were almost unknown outside the country. In 1854 the government started to trade with western foreigners, but it took until the 1970s for the Tosa to find its way to Europe and in the early 1980s the Tosa was imported into the United States. The first Tosa registered in Europe was probably a bitch, Fujimusumu, in 1976. A male, Tomitake, was registered in 1977. The first European litter Tosa's was born in the late 70's or early 80's. Dutch history began in the early 1980s with a Tosa imported from Germany. With great effort 2 additional Tosa's were imported from Japan and the Dutch breeding program was started.
The Tosa is a strong, muscular dog with a loyal and protective temperament. They are excellent guard dogs and are agile athletes given their size and weight.
The Tosa temperament is characterized by patience, calm and courage. A typical Tosa has a strong character. A Tosa is not likely to show aggression unless challenged. They are generally patient and adapt to changes in the family. They are gentle and playful with children, but supervision with such a large dog with children is necessary.
The breed is characterized by an extremely high pain tolerance, which can be annoying because they do not show anything quickly in case of illness or accident. Any signal of pain or weakness that is seen gives reason to take this seriously and have it checked by a veterinarian.
A Tosa will not relapse when challenged. Males have a stronger character than females. It is extremely important to properly socialize and train Tosas from puppyhood. It is not a breed that needs a hard hand, but is very sensitive to the tone of the voice. Applying this properly is important for mutual respect.
Positive reward training in the form of treats works well for Tosa's. They are intelligent and can be trained in obedience well. Consistent and clear communication are of utmost importance and form the basis of a good relationship between boss and his / her Tosa.
They can sometimes be very stubborn and tenacious. As a boss you need to be confident enough for this breed, for that reason it is not a good choice to have such a dog as a first dog. Inconsistency can lead to problem behavior, which of course is true for many dogs.
It is a quiet breed that only barks when necessary. When properly socialized, they get along well with other animals such as horses, cats and other dogs within the "pack". It is not always the case, but animals outside the pack are not easily tolerated.
Tosa is classified in FCI group 2 - Pinschers and Schnauzers, Molossoids and Swiss Mountain Dogs
A Tosa should not have a light physical construction. The broad head has clear wrinkles, which become even more visible when the dog is alert. In bitches the head is not as wide as in males and it should look more feminine. The Tosa has a strong jaw and the teeth form a scissor bite. The black around the eyes absorbs sunlight and prevents reflection of sunlight in the eyes. The muzzle can be the same color as the coat or black, with a black nose. The ears have a V-shape and are considered drop ears, which means that they are not erect. The hair on the ears is super soft.
A Tosa also has a characteristic dewlap. In males this is stronger visible than in bitches.
The high withers, straight back, slightly curved croup, broad chest and raised belly give the Tosa the appearance of a strong muscular athlete.
The coat is short, hard and dense. Color ranges from fawn, red, black and brindle. Light white marking on the chest and feet are common.