I have recently become aware of a new California law (effective Janaury 2018) which prevents employers from requesting salary history to potential hiring candidates: https://leginfo.legislature.ca.gov/faces/billTextClient.xhtml?bill_id=201720180AB168
However, a very large Silicon Valley-based company with a branch in Japan is indeed requesting this information for a position based in Japan (prior to an offer of course).
I am confused about if this law would apply to the company even in Japan.
All I have been able to find out is that the Japan branch is a "100%-owned subsidiary" of the California-based HQ, and even with that information I am not sure how the law applies.
(If it's relevant, this question would apply to an applicant that is a U.S. Citizen/California non-resident and currently files both California State tax and Federal income tax, and the previous company worked at would be a Japan-based one.)