Not to be persnickity, but that's a little off.
Tosas are one of the smaller mastiffs. They were one of the only mastiff-type breeds bred specifically for dogfighting instead of protection, and smaller, more agile dogs were more desirable. I was fortunate enough to know a Tosa owner when I was a kid in Hawaii, and he filled my ears with tons of that stuff. LoL, just as dog-mad as the rest of us.