Some preperation for Essays in Social Geography:

The Three Regions of Japan:
The Kanto Plain lies in the hinterland of Tokyo, around Nagoya is the Nobi Plain, and around Osaka is the Kansai District. Each of these regions are major farming zones and are at the heart of Japan's manufacturing complex, so they're under constant urban pressure. The Kanto Plain is Japan's dominant urbanization region and contains 1/3 of the population. The Kanto Plain is focused on the Tokyo-Yokohama-Kawasaki metropolitan area, with its natural harbor at Yokohama. This area is the central location for the whole country, and many businesses choose Tokyo as their headquarters. However, the Kanto Plain has a constant valcano threat and can't produce enough food for its population.
The sencond-ranking economic region is the Kansai District, which involves the Osaka-Kobe-Kyoto triangle and is located at the Eastern end of the Inland Sea. Osaka used to be the major base for Chinese trade, but since World War Two Kobe has remained a busy port. This is an important farming area, mainly for rice, but it still needs to have food imported. The Kansai district is smaller agriculturally than the Kanto Plain.
Between the Kanto Plain and Kansai District lies the Nobi Plain, which is Japans leading textile producer. Larger than the Kansai District, its agriculture is better but still not as good as the Kanto Plain. This region revolves around Nagoya, whose port is not as good as Tokyo's or Osaka's.
The Koreas:
The Koreas became divided because the Allied Powers decided to devide it for administrative matters after World War Two. North of the 38th parallel lies North Korea, which belongs to the Soviet Union, and south of it lies South Korea, which has had lots of US aid. At the end of the Korean War, a cease-fire line drew a de facto boundary. These two countries have regional complementarity, because North Korea has raw materials and fertilizer and South Korea has food. North Korea trades with China and the Soviets, and South Korea trades with the US, Japan, and Western Europe.