Can't a Japanese visa last more than 15 days now?

The stay time of Japanese tourist visa has been 15 days. It is valid for three months, and you can go to Japan at any time within three months. From the date of entry, you can stay for 15 days, and leave before 24 o'clock after 15 days (including 15 days). If you don't go to Japan for three months, your visa will automatically expire and you need to apply again to go to Japan. This is the general situation. If you are in Japan for some special reasons, such as force majeure such as natural disasters or other special circumstances, you can apply for a temporary extension of your stay to 30 days, but generally speaking, it cannot be extended.