Hibiscuses are as ubiquitous in Okinawa as they are in Hawaii. However, they are generally popular summer garden plants in the rest of Japan.
I learned from my florist that fuyo which is the Japanese hibiscus is a temperate flower and can survive winter well. Most of the imported hibiscuses that you see (except I think the white one which looks like a hibiscus syriacus) must be taken indoors before the cold weather sets in.
NATURE IN JAPAN 