Japan passed the Immigration Control Act in 1990, but they still only issue visas to skilled workers.

"Ultimately, Japan passed the Immigration Control Act in 1990 which opened a side-door to ethnic Japanese (up to the third generation) living in other countries, allowing them to immigrate to Japan for the unspecified purpose of performing unskilled labor; Japan still does not issue visas to anyone but skilled workers. By adding this provisionthey must be ethnic Japanesethe government had addressed the sakoku arguments by preserving racial homogeneity (despite the glaring cultural and linguistic differences), but also compromised with those in favor of kaikoku by allowing a legal loophole providing for immigrant unskilled labor. This caused a large influx of Japanese Brazilians, termed Dekasegi.

Today attitudes in Japan often remain decidedly negative towards immigrants, legal or otherwise, and new tighter controls are currently being drafted, according to the Japan Times.

Negative treatment of foreigners turns away potential benefit that countries obtain from immigration. New skills, cultures and ideas are plentiful in immigrant populations. Opposition to immigration decreases the chance that new ideas and skills increase the domestic production of a country."

Source:"Opposition to Immigration" is a difficult qualitative factor to overcome, so the investment will have to spend a lot of time trying to overcome this issue.