Osaka: Magical Shopping Arcade Abenobashi. You can see such shotengai in real life Osaka as well. Also uses exclusively Kansai-ben.
Hiroshima: In This Corner of the World. It made me cry 3 times!
Fukuoka: Manga Bambino! An Italian food manga with a ca. 22 year old protagonist. I dearly dearly loved this manga when I was around the same age. The protagonist is from Fukuoka. This manga was one of the reasons that inspired or motivated me to learn how to cook properly. I liked everything about it: the drawings, the story, the content, the characters, how to navigate the world as a young adult.