What are the advantages & weaknesses of Japanese against Roman warfare?

[Madae]

In the grand scheme of things, I'll bet on a professionnal army with good discipline and tactics, over a bunch of individual fighters, regardless of their individual skills. As said before, there is never a guaranted victory in war, and every single army lost several battle to opponents that were supposedly inferior in any way but, overall, history tends to reward leadership, technology and organization more than movie picture of badassery.

I agree with this. There is no doubt that, warrior to warrior, the Japanese were superior. But in terms of military strategy and tactics, I believe the Romans would come out on top in that fight. Japanese battle consisted of man-to-man, where Roman fighting and tactics consisted of army-to-army (if possible). Most of what the legion came across could not grasp this concept, and that is why they failed. Unless the Japanese were willing to adopt a different strategy (highly doubtful), they would have fell just like the rest. Some people probably look past this because they have a love of one culture and history over another, but the simple truth is there; the Romans were organized and trained to fight together - the Japanese were organized but trained to fight one on one. Knowing their disposition towards foreign ideas, it would not have been easy for them to adapt to such a different style of fighting. Just look at what happened during the Meiji Restoration; while the rest of the world was moving into the modern era, the Japanese up until that point were forcefully isolating themselves. It only changed when they were forced by the ruling classes to do away with the old ideas (which caused a civil war), and that is something that came with the empowerment of the peasant class - which is something the Romans had been doing a thousand years before them with citizenship.

On a side note; the Romans conquered much of their known world using the same tried-and-true tactics... the Japanese never made it past Korea. Granted they were much more isolated, but it just goes to show that if the Japanese were truly a powerhouse, they would have had much more luck getting out of Japan. They simply weren't unified, or cared, enough to do what needed to be done, which is something the Romans excelled at.