Should I take enclosed shoes or will sandals be fine everywhere?

I have a foot condition which makes wearing enclosed shoes painful. I wear my sandals literally everywhere in Australia and am wondering if I can do that in Japan as well? Will it be fine in all of the theme parks, shrines, etc?

I am only taking a carry on bag so don't want to waste my allowance with a pair of enclosed shoes that I won't use. Any thoughts welcome.

Thanks!