Check your local government for details
It's the official My Number app. Most modern phones have a card reader built in so can read the plastic My Number card. This allows you to log into the official app and access government services.
Links for Sendai and Tokyo?
Sendai: https://www.city.sendai.jp/kuse-kikaku/seikatu/ouenpointo.html
Tokyo: https://www.tokyoapp.metro.tokyo.lg.jp/news/260202370.html
It's the official My Number app. Most modern phones have a card reader built in so can read the plastic My Number card. This allows you to log into the official app and access government services.
Links for Sendai and Tokyo?
Sendai: https://www.city.sendai.jp/kuse-kikaku/seikatu/ouenpointo.html
Tokyo: https://www.tokyoapp.metro.tokyo.lg.jp/news/260202370.html