[Jaidann]

Bad Idea!!!! The Tosa Inu was bred for fighting. In fact, if you do some history research on the Tosa Inu, the Japanese used to have their samurai warriors study these dogs. Here is a little excerpt ....

In Japan today, dogfighting is still practiced; and the Japanese revere the Tosa as the embodiment of a warrior. Historically, the Samurai were instructed to study the Tosa during combat to learn fearlessness, tenacity, and courage. Surprisingly, the rules governing Japanese dogfights are stringent and complex, and the Japanese have ennobled Tosa dogfights with all the pageantry and ceremony of Sumo Wrestling. In Japan; the Tosa is referred to as the "Sumo" dog because of its’ great size and strength. Recondite and metaphorical, Tosa dogfights are not fought to the death. In Japan; unbridled aggression or expedient victories are discouraged in dogfighting. Anthropomorphized to be warriors, in the fight arena; the Tosa is judged: by the duration of the fight, the quality of the opponent, courage, and endurance. A combatant is more highly respected If he fights courageously and for longer durations. Those competitors with many "quick wins" will be ranked lower than the competitor who routinely lasts the duration of the 30 minute bout.

Your OWN post should have given you the answer to this....

"Question - the Tosa (near 180lb) is huge, a lot bigger than my Rott (100 lb) and all muscle and I have no doubt that he'd tear him apart if it ever came to a fight (no way I'd step in if that ever happened, I ain't suicidal)"

Ask yourself...WHAT IF? Do you not value your Rottie enough and have enough common sense to tell your friend to find something else to do with HIS dog. Why put yours in harms way? If your friend cannot understand the danger of this .....personally, I'd be looking for new friends.