Question: how much money do you need to retire in japan?
Answer: You can pay in up to ¥1.2 million a year for an adult, and ¥0.8 million for a child, so a family of four could invest up to ¥4 million a year and not pay taxes on dividends or capital gains. You can access your investments at any time so it's more flexible than iDeCo, but it won't reduce your income taxes.