Japan has, by some measures, the highest inheritance tax rate in the world. It's so high, and the related laws and rules so unforgiving and complicated, that a smart move to the country can years later suddenly look like an expensive mistake.

The tax even compels some residents to abandon Japan altogether.

“It’s very easy to get into the higher rates of inheritance tax compared to in other countries,” said Adrian Castelino-Prabhu, a principal at Grant Thornton specializing in international inheritance and gift taxation.