Kirk with some information on the “Green Vision Expo” (in Japanese this is the くまもと 花とみどり の 博覧会 or くまもと花博 [Kumamoto Hanahaku] for short).
First, the English you see is from the following address:
https://kumaryokkafair.com/assets/ryokkafair_outline_en.pdf
It’s nicely done but, unfortunately, it seems that this one pdf is all there is. So, if you want to take advantage of the free shuttles between the three areas (City Center, Waterside, and Machiyama [Tatsutayama]), you need to look at the Japanese website. The image you see is from an RKK segment that ran today. It seems that the city is spending 16 million yen (about $130,000 USD) to pay for free transportation that very few people are using. I can’t translate all of the information on the Japanese page but I can tell you that there are schedules and information there in Japanese about how to get free rides (via taxis in some cases!!) between the venues. Check out the “access” (アクセス) information on this site:
And, I learned about the free 20-minute taxi rides from downtown to Tatsutayama here: https://rkk.jp/news/index.php?id=NS003202204041702090111
Finally, one thought about name confusion: I wouldn’t be surprised if quite a few Japanese people who were asked about the “Green Vision Expo” failed to realize that it was the English term for “Hanahaku.” Translations help us English speakers understand the gist of an event, even if we don’t understand Japanese, but lack of a common event name (even in parentheses would be enough) can cause communication problems.