This is how much governments are hurt when there are no taxpayers. They need those taxes to pay coupons on government bonds
Otherwise they will be borrowing say 16% more per annum to afford 5% per annum in bond coupons. Thankfully Bank of Japan doesn't expect any bond coupons. They are lending the Government of Japan 100.1 Yen for every 100 Yen they expect back at maturity. So in other words Bank of Japan is willing to suffer a small loss raising for negative yield by lending to the government
Other countries may not be so fortunate to last this long with yield curve control (i.e. fixing the price of all bonds)
