Where to go Kumamoto at night ?

I will be arriving 5.17 pm. It will be too late for the garden and I leave 9.44 am next morning for the SL Hitoyoshi train return that will take up my whole day. My only free hours at night, which area is nice to explore ?

I recommend to dine at the Umazakura horse meat restaurant:
http://www.umasakura.com/

If you arrive by train you can take the street car from the station down to the castle and walk through the covered shopping arcade. Next to the arcade is one of the major nightlife areas of town if you're up for that. You can also walk around the outside of the castle to view the walls. If you arrive at the Kotsu Center by bus, you'll be next to the arcade and castle.

You might consider Hanaokayama, which is near Kumamoto Station and has a good night view from the top. There is also Mt. Kinpo but unless you are driving it is about an hour on foot to the top - great night view of the city though.