Japan's exports in the month rose 2.4 percent from a year ago to 5.98 trillion yen ($78.2 billion), the second straight monthly increase.
Meanwhile, imports soared 12.1 percent to 5.68 trillion yen, rising for 21 straight months mainly due to higher energy prices.
But the figure was 61.2 percent lower than the level seen last year, reflecting the severe damage done by the March earthquake and tsunami, particularly to the supply chain.