Osaka University is located in Osaka (Kansai) and Hokkaido University is located in Hokkaido (North), both of which are national universities.
Due to economic reasons, tuition in the state is cheaper, and the living expenses in Tokyo are relatively high.
If the language is considered, the natural Tokyo circle is better.
I don't know if there is an architecture department, so I suggest checking their official website.
Personally, I think there are more schools in Tokyo, and there are more opportunities for exchange and study. Keio is quite famous and should be a good choice.