Lump-Sum Withdrawal Payment from the National Pension
To receive a lump-sum withdrawal payment from the National Pension, you must meet all of the following conditions: you do not hold Japanese citizenship, you are no longer enrolled as an insured person, you have at least 6 months of paid contribution periods, and you do not meet the qualifying period for pension benefits. The payment amount is calculated based on the premium amount and the number of months for which premiums have been paid. Since April 2021, the upper limit on the number of months used in the calculation has been set at 60 months, and the maximum payment amount is 537,600 yen.
Source
日本年金機構
This information is reference material based on official announcements. Always verify accurate information on official websites or with relevant authorities.