Chinese and Japanese swordsmen did come into contact with one another at least once in the last millenium. It’s documented in “1587 - A Year of No Significance : the Ming Dynasty in Decline,
By Ray Huang.”
Unfortunately, I don’t have the book with me, but here’s what I remember (take all numbers with a grain of salt)
The players:
Local chinese soldiers and Officers who have seen limited combat, if any.
Weapons - swords and spears, drilled infrequently and in regimental style.
Japanese pirates attacking the chinese coastline from Shan Dong to Hai Nan island.
Weapons - Two single edged Japanese swords, giving an operational diameter of 16 feet.
The local chinese Garrisons were wholly unprepared for these attacks, at least initially. The Japanese generally came in with a small force of about 15, and easily overcame the larger chinese force, whirling through them with their two swords. The problem was training and experience - most shoreline garrisons had faced little action, and were drilled according to mass army theory too boot. When faced with a small force of independent fighters, they were at a loss, and got slaughtered.
The chinese even tried “heroes.” Pitting a Mercenary against the pirates, they thought to solve the problem in a propaganda-friendly way. Here, the larger force prevailed, with the pirates carving the lone warrior up.
In the end, it was a general whose name I now forget that saved the day. He’s famous though. He retrained the army, and invented the mandarin duck formation.
Mandarin duck formation
2 guys in the front with swords and shields.
2 guys behind them with spears
2 guys behind them, one with a birch tree (yes, a birch tree) and one with an bow.
The guy with the birch tree (get this) pinned the pirate down. The spearmen stuck the pirate, the bowman shot the pirate, and the swordsmen defended the front line from any errant swing of the pirate’s sword. This worked really well in alleyways and on bridges.
So, basically, the Pirates initially had the advantage over a limp chinese army that had little current experience. They also had the advantage over the chinese mercenaries, who had more experience than the army, but whose fighting calibre is unknown.
After a quick retrain and a newly adopted tactic (the birch tree was substituted for a long iron pole with snags on it later), the Chinese prevailed, and drove the invaders out.