The number of foreign nationals entering Japan in 2011 dived 24.4 percent from a year earlier to 7.14 million, down 2.31 million, marking the sharpest decline in both rate and number since 1950, when officials first compiled comparable data, according to government data.

The Immigration Bureau of the Justice Ministry cited the 11 March earthquake-tsunami disaster and ensuing nuclear crisis as well as the yen's historic appreciation as factors for the drop.

The monthly breakdown showed that foreign arrivals plunged 46.2 percent in March and 54.5 percent in April due to the disasters, but the margin of decline was narrowed to 11.6 percent in November and and 10.4 percent in December, the bureau said in a preliminary report.