[pandem]

Osaka has a central circle line, Osaka Loop Line. https://en.wikipedia.org/wiki/Osaka_Loop_Line

The main stations along this line are probably Kyobashi and Tennoji, the latter of which has at least the tallest building in Japan.

I would mainly divide Osaka in two centers, with Umeda being the CBD and Namba/Shinsaibashi area to be the center for people going out.

[quicklime]

Ah you're right, I don't know how I missed that! I guess it just doesn't follow the city's main neighborhoods like Tokyo's one does. There goes my theory...