Inventor Remuneration Around the World

Article 35 of the Japanese Patent laws provide for "reasonable remuneration" from the employer when the employer takes assignment of patent rights. In my first reading, the Japanese law does not appear to include a limit to only Japanese employers. In fact, such a limitation could arguably be a violation of the country's obligation of national treatment. Is there a definitive answer to whether the Japanese law applies to all patents filed in Japan or only those originating in Japan? Do other country inventor remuneration laws apply to US companies filing US initiated inventions in that country?