Data from Japan's Ministry of Finance earlier showed big buying of foreign bonds.

The week ended September 9 saw Japan buy 3.6tln yen of foreign bonds, analysts in the time zone are describing it as a 'massive' result. If you check out the graph below you'll see it was a biggie.

Via Reuters:

Japan buying foreign bonds 14 September 2023

Some fingers pointing at this catalysing the yen bid we are seeing so far. I'm not buying that but I see their point.