I have been told that Japanese immigration bureau was very hard to issue visas to foreigners.

As far as I checked, Immigration policy of Japan became stricter than before recently.  Japanese government thinks that immigrants sometimes live poorly and cause social unrest by studying the experience in the UK where immigrants and their first and second generation are reported to become terrorists because some of them have failed to adapt themselves to the society.
In reality, the number of crimes committed by immigrants are increasing and their children fails to match adapt themselves to public schools.

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　→Article