Since the import slump means that the region is bringing in fewer raw materials and intermediate goods for manufacturing, it implies a continuing export downturn.
China is a prominent export-processing economy, which means that its factories import lots of raw materials and intermediate goods to stoke the machines and processes that manufacture and assemble the finished goods it exports to the United States and elsewhere.
The recklessness of that action sent shock waves through the boardrooms of every Japanese company that has come to rely upon China not just for raw materials, but for intermediate parts and, of course, for finished goods.