EdotenBlack Setta Japanese Tatami Zouri Sandals

If i have size 9 feet, should i get xl or xxl?

Will the 3xl work for a US size 16?

Do you have to break them in? I got them today and it kinda hurts a lot though they are big enough.

I am 9.5 in men size, what size should I get? I have rather wide feed.