HAS59 - and there in lies one of the strengths of the P-8, we have trained crews in the US, who have been involved in the development and intro to service with the US Navy.
I believe some of the Seedcorn crews went to fly P-3 with other friendly nations, so maybe we have a cheaper prop option available too.
Increased Defence links with Japan allows the Kawasaki a look in but we have no-one ready trained in how to fly/fight it.