I want to go visiting Kumamoto next month, so are there any suggestions please? It will be great if you can provide me with some restaurants as well.

I had taipien, a noodle soup popular in Kumamoto, that originally comes from Chinese cuisine.

Kumamoto has many unique dishes. You can read about them, and some restaurants, on the Kumamoto official website https://kumanago.jp/en/spots/dining/

Katsuretsutei for tonkatsu and Tengaiten or Kokutei for ramen!

If you can head out towards Aso, go to Keystone Garden for Japanese/French fusion. https://en.japantravel.com/kumamoto/the-keystone-garden/21592