Ming was a Dynasty, and the Portuguese were a kingdom. Dynasties and Kingdoms have differences. Usually in Ancient China, Dynasties would easily allow for Emperors to become corrupt over time. After an emperor is killed, usually a child emperor would come along, just like European Monarchs and other Monarchs around the world. Except, two factions called the Eunuchs and the Warlords would try to effect the gullible Child Emperor, eventually tearing Mings politics apart until someone takes control. In Portugal, similar things would happen, such as the Religious Factions, and the Military. They would both fight over power, and pretty much the same thing would happen. The Military would often win, because they are skilled fighters.
Some Japanese men actually went and got recruited and joined the army. The majority of them went to a type of POW camp. Overall they still like being American and didn’t like the persecution they felt from the public and the military.