A glance at the IJN (Imperial Japanese Navy) in the pacific theater WW2, is powerful evidence of what kind of Navy Japan, an island nation, can put to sea.
It doesn’t surprise me in the least what you saw at Kure. The destroyer I was on, by the way, back in the 60’s, visited Kure...as I remember several times.
In my opinion, assuming Japan doesn’t decide to return to their hegemonic Naval ways of years past, the US couldn’t have a stronger Naval power as ally.
Perhaps, after the passage of so many years, Bushido has become a cultural artifact.
They no longer have the ability or will. They do need to be VERY concerned that they do not allow China to establish regional hegemony. China has both the ability AND the will. In fact, they have a plan and are executing it. Japan, South Korea and Taiwan have a combined GDP of only about half that of China, and unless they are ready to accept their new Chinese masters, they better get together with a coherent plan themselves.