I take it that the KIX-SFO flights will not have any PJs due to the relatively shorter flight?

Also, are the PJs and amenity kits catered/ loaded specifically for a flight and its return? Or are they loaded on a plane just to keep them in stock?

I was on the return SIN-SFO and by the end of the flight, there were loads of PJs and amenity kits left, that the lovely chief purser was handing them to GS who were seated at the back.