Tax obligations in the year of moving to Japan on a spouse child of Japanese national visa

If someone is planning to move on such a visa, table 2, at a mid point in a year what are their obligations regarding taxes:

Income earned overseas in the first half of the year?

Overseas capital gains realized prior to receiving the visa?

Gift duties on gifts given in the first half of the year?

Is there a 183 day rule that comes into effect?

by Jyontaitaa