Although the Japanese have extensively migrated to western South America (Chile and Peru), Japan is much closer to Spain (6700 miles, 10800 km) than to Argentina (11,000 mi or 17,700 km).
This is mainly due to the width of the Pacific Ocean, which conversely makes travel to South America more direct. Also, flights from Japan to Spain could use the trans-polar route north of Russia, making it even closer.
Japan and Spain are both centered near 40° N latitude, while Argentina is at least 22° south of the equator.
Iowa and the Midwest are closer to Spain than to Argentina. The SW and southern states are closer to Argentina.
Montana and the northwest US are closer to Spain than to Argentina. Southern and southwestern states are closer to Argentina.
In Argentina, you closer to northern than to Spain in southern.
Spain is closer to North Carolina than is Argentina. States farther to the south and southwest are closer to Argentina.
Like most of the US, Illinois is closer to Spain than to Argentina.(Some southern locations of the US are closer to Argentina.)
Like most of the US, Massachusetts is closer to Spain than to Argentina.(Some southern locations of the US are closer to Argentina.)
Like most of the US, Michigan is closer to Spain than to Argentina.(Some southern locations of the US are closer to Argentina.)
Like most of the US, Wisconsin is closer to Spain than to Argentina.(Some southern locations of the US are closer to Argentina.)
Like most of the US, Connecticut is closer to Spain than to Argentina.(Some southern locations of the US are closer to Argentina.)
Like most of the US, Ohio and the Midwest are closer to Spain than to Argentina.(Some southern locations of the US are closer to Argentina.)
All of Texas, as with other southern states, is closer to Argentina than to Spain. Most of the northern and northwestern US is closer to Spain.
All of Texas, as with other southern states, is closer to Argentina than to Spain. Most of the northern and northwestern US are closer to Spain.