Terminology
Trade in fact prospered during this period, and though relations and trade were restricted to certain ports, the country was far from closed. In fact, as the shogunate expelled the Portuguese, they simultaneously engaged in discussions with Dutch and Korean representatives to ensure that the overall volume of trade did not suffer. Thus, it has become increasingly common in scholarship in recent decades to refer to the foreign relations policy of the period not as sakoku, implying a totally secluded, isolated, and "closed" country, but by the term kaikin (海禁, "maritime prohibitions") used in documents at the time, and derived from the similar Chinese concept hai jin.
Read more about this topic: Sakoku