(Fiona) Kumamoto is hosting an autumn version of the Green Vision Flower Expo that was held earlier this year. As before, events are taking place in three main areas - Ezu-ko, Tatsuda-yama and the city centre. I found this out by chance while on a walk in the woods this afternoon - alas, I'd missed the outdoor concert and Mori Marché but I believe they will happen again tomorrow. Details can be found here, with English translation available.
https://www.city.kumamoto.jp/hpkiji/pub/detail.aspx?c_id=5&id=44499#