Sony has been moving to the West for years. Japan is kind of becoming less and less relevant in terms of console gaming and other markets in general.
The question remains about US headquarters vs Europe headquarters, however many global companies stick to the States, so no surprise for multiple obvious reasons.
God bless You.
When PS4 will hit 100m consoles sold: Before Christmas 2019
There were three ravens sat on a tree / They were as blacke as they might be / The one of them said to his mate, Where shall we our breakfast take?