California, officially the State of California, is a state in the western part of the United States. It is the third largest state by total area and the largest by population in the United States. Its largest cities are Los Angeles, San Diego, San Jose, and San Francisco. The capital is Sacramento. It is bordered by Arizona to the southeast, Oregon to the north, Nevada to the east and the Mexican state of Baja California to the south.

South Korea, officially the Republic of Korea, is a country in East Asia, constituting the southern part of the Korean Peninsula, and sharing a land border with North Korea. 25 million people, around half of the country's population of more than 51 million people, live in the Seoul Capital Area, the fifth-largest metropolitan area in the world.