Now, I'm not a fan of gardens normally. They're not to visit as tourists/travelers, they're to go and have a break from the chores of everyday life. This one park, though, was worth a visit so much so that we walked every inch of it, and then did a second round to make this video. We were to do a third one also but didn't as we had some more stuff to do during the day, which was saddening.
Kumamoto is a nice place. It's a daytrip for many, my wife said, and rarely people spend a night or two there. As one that loves every part of Japan, I'd say spend a night or two at least, and give at least two hours for this park in your plan - well, if you'll like what you see, of course. Watching it before uploading here, I should say that the recording doesn't do it justice and it's lot more beautiful in person, but it's for you to decide for yourself, of course.
For the (potential) travelers in Spring: There's the Sakura-no Hiroba (cherry tree square), where there's a walkway on both sides of which are cherry trees. It should make a pretty view for your photos and videos. Sadly the trees don't show their beauty in September. Not all trees are as beautiful as pine trees all year round. Sadly.
