Housing is absolutely an investment vehicle in Japan. It's just that Japan has been economically stagnant for 30+ years, bordering on deflation, and anywhere outside of a first- or second-tier city is effectively dying. Couple that with the Japanese cultural distaste for pre-owned housing, and this is the outcome.

If you operate a rental in any area outside of the core of the major cities, you are in the business of charging a huge monthly premium over a property value that is rapidly depreciating to zero. This is fundamentally different than the US.