Last year stayed in Onna, now would like to stay on a small island off Okinawa

I am travelling to Asia again this year and would like to come back to Okinawa in October.

My plan is to stay on mainland and take a diving course, but after wanted to stay on a small island around Okinawa. Can fly or take a ferry, any suggestions?

Looking for nice or unique wildlife (animals), and a bit small pace than Okinawa but it would be amazing if the place would not be too hard to reach and have some shops/activities there (not too deserted 😅)

Thanks