I'm no expert, just a virtual tourist via YouTube.
According to (1) average Tokyo apartment size is 20 square meters or a little over 400 square feet vs 700 square feet in San Francisco as found from a quick Google search.
Considering some Japanese rent and live in Cyber cafe cubes that are even smaller I'm not sure how fair a comparison really is between the two. Japan in particular seems to have small appliances geared towards smaller footprint apartments.
https://www.all-about-teaching-english-in-japan.com/Tokyoapa...