As of yesterday, Wednesday, April 10, 2024, it now takes ¥153 to get $1. The Bank of Japan can strengthen the ¥en by selling US government bonds. They could then sell the dollars that they get from the bonds for ¥en on the open market for less than ¥153. It is a cheap trick, but it will yank around the Federal Reserve, who will need to be the lender of last resort to the US government if Japan and China are selling. That means more inflation for the USA, and a weakening US dollar. Talk about YinYang!