Question on Japan high tax rate on U.S. Social Security payments.

In U.S., social security payments can be virtually not taxed at all or a very small amount, depending on payment amount. If you are near max social security, around $4500 a month, its still only small or not tax. Japan, taxing all U.S. income, however taxes U.S. social security at the same rate as any other income money. With yen conversion, 7.2m yen of U.S. social security triggers a 20-25% tax rate which is brutal. A big piece is health insurance if not in a company, it can be 650,000 yen to 900,000 a year. Question – has anyone found a way to "beat" this super high tax rate on U.S. Social security payments living in Japan? Or a way to substantially lower the amount taxed? Thanks