We use a large dataset of Japanese manufacturing firms to investigate the effect of the late export boom to the productivity growth and various productivity enhancing investments by exporting firms. We find that large exporters enjoyed significantly higher productivity growth over non-exporters while it was not the case for the small exporters which constitute a large mass of Japanese exporters. We also find striking evidence that only the exporters serving worldwide actually enjoyed significant advantage in productivity growth, and not those that exported only to Asia which corresponds to about 50% of small exporters. On the other hand, we find that both large and small exporters engaged in more intensive innovation activities and capital investments. Therefore, although the late export boom did not reward all exporters in an even way, it did encourage wide range of exporter investments that should enhance their productivity. Export boom is thus the case where exporters build up productivity advantage over non-exporters long after their entry, offering additional explanation on the formation of universally observed exporters' "premium" on productivity level.