Kirk here. Sorry for the last-minute notice but today (8/5) is the day of the Hinokuni Matsuri So Odori or Otemoyan (big dance?). The picture is of a previous year, I think, and was taken from the following site:
https://kumamoto-guide.jp/hinokunimatsuri/
The site is only in Japanese. Personally, I’m slightly dismayed by the lack of publicly available information about today’s even in English. For a general explanation about the festival in English, I recommend the following:
https://ohmatsuri.com/en/articles/kumamoto-hinokuni-matsuri
For details about today, I think the Japanese site is all there is. Still, even if you’re not fluent in Japanese, you can check out the maps and use machine translation services to check out text that interests you.