Answer:
Portugal.
Step-by-step explanation:
The first contact between Portugal and Japan dates back to 1543 when the first explorers arrived. Those explorers were Antonio Da Mota and Francisco Zeimoto. The Japanese named then "Nanban" which could be translated as "Southern Barbarian" to refer to first Portuguese explorers and further in time to all the Europeans who traded with them.
In China, the Portuguese explorers arrived a couple of decades before, by the year 1517, but it was not until 1550 that they were granted the right to trade with that nation. The Portuguese settled in Macao and used it as a base to trade spices and other Asian goods to Europe.
I hope this answer helps you.