Isn't hirame also flounder?
So I did some reading up (too many types of flatfishes!!!) and hope I got most of my info right... Hirame/平目 has its eyes and mouth on the left side, has a firmer texture due to swimming around to catch prey and in-season during summer; while Karei/鰈 has its eyes and mouth on the right, is bottom dwelling and hence has a softer richer texture, and in-season during winter.
It's interesting that Hirame is seen as a higher class of shirodane compared to Karei but anything when in-season always wins 🍣 #omakasesushi #latergram #sashimilover #burpple