Apple continues their slow rollout of Indoor Maps for Japan. Tokyo Narita and Nagoya Chubu Airport indoor maps were added in September (Haneda and Kansai are still missing). Indoor Mall Maps have been added for a few Tokyo locations. So far I have identified Kitte, the old post office site next to Tokyo station, Ginza Six, Roppongi Hills and Omotesando Hills. There are probably more in other metropolitan areas but we won’t know until Apple updates the iOS Feature Availability page which can take forever. Underground station mall maps for important places like Tokyo, Shinjuku and Ikebukuro are missing, unfortunately. Good luck navigating those monster mazes on your own.
Apple has obviously gone for indoor mapped areas where the data is readily available from a single 3rd party source. Underground station areas have multiple sources and agencies to deal with and Apple doesn’t do much data collection in Japan yet . Until they do it will be a slow go.