Depends on where you’re located, but typically through their online store, or a stockist.
I think they only stock up to size 4 (Japanese XL).
us.isseymiyake.com/products/hp6...
^this isn’t the exact shirt but a variation on it from this season.
(I did not pay retail price for ours)
us.isseymiyake.com
MONTHLY COLORS : AUGUST
This shirt with an open collar is available in color tones inspired by the soft shadows of evening. It offers portability and lightweight comfort, with the quick-drying property unique to polyester. I...