William Adams, the historical figure which the character John Blackthorne was based on, spoke a number of languages, including Portuguese.
The wife of a Samurai would receive a small tanto called a kwaiken, a small dagger, as a wedding gift.
The wives of the samurai were trained to protect the home and village when the samurai warriors were away at battle.
Magellan's Pass refers to Strait of Magellan is a 350-mile navigable passage between the Atlantic and Pacific oceans. It's located in the southernmost part of South America, between Chilean Patagonia and the Tierra del Fuego archipelago. It was named after Ferdinand Magellan, a Portuguese explorer who led the first successful attempt to circumnavigate the world. He planned and led the 1519 Spanish expedition to the East Indies across the Pacific Ocean to open a maritime trade route, and achieved the first European navigation to Asia via the Pacific. He died during the expedition, but his crew picked up the mantle.
As Portugal was not as populous or militaristic as Spain, it generally did not conquer indigenous populations or even create colonies with the goal of settling them - the Portuguese instead operated many feitorias (fortified trading posts) in coasts around the world in Brazil, the west coast of Africa, the Cape of Good Hope, western India, southern China, and finally in the artificial port of Dejima in Nagasaki. The Japanese received the Portuguese with much suspicion, especially as the Portuguese were interested not only in trading with the Japanese, but converting the Japanese to Christianity. The spread of Christianity to Japan would cause much social turmoil and political discontent, as the Shogun and many daimyo considered the new religion to be a threat to their authority and Japanese traditions, and did their utmost to exterminate it. Eventually, the Portuguese were expelled, but Japan had since been opened to limited European trade, and the Portuguese were soon replaced with the Dutch, who made no attempt to proselytize and restricted their interactions with the Japanese to trade.