The statement at the end of the announcement on the last page on its monetary policy has left traders in shock. This appears that the BoJ realizes that it now effectively has destroyed its bond market and realizes that there is not only the end of a free market, but there is a contagion of surrounding lack of liquidity.
https://www.armstrongeconomics.com/world-news/central-banks/bank-of-japan-the-bond-crisis/