I don’t know how to choose between Hokkaido and Shikoku for my 2nd trip in Japan in september.

I already visited Tokyo, Kyoto, Nara, Osaka, Hiroshima and the japanese alps in 2023. For my 2nd trip i wanted to visited a new region, i'm thorn between Hokkaido and Shikoku. I love both nature and culture, it's reallt difficult to decide.

I'm looking for advice from your experience. Hokkaido been less hot than Shikoku is a good point, but as a solo travel i fear that i'll get bored in Hokkaido by myself for 10 days.