This extensive article discusses various ways in which Kumamon is being used to promote tourism.
https://japannews.yomiuri.co.jp/features/travel-spots/20230902-133726/
It says that Kumamon Square is is located in the “Tetoria Kumamoto Building,” which probably won’t help most people find it. Here’s a page that shows its location in the Tsuruya Department Store downtown:
Note that “Suidocho” should be capitalized. – Kirk