Given that about half of Amazon’s “reviews” are basically “I didn’t read anything and ordered the wrong thing. 1 star.” I wouldn’t expect it to be a joke.

I dunno, I’ve seen certain publishers of manga in English put big warning pages on the back (or what people might assume is the front) saying things like “Hey, you’re starting on the wrong side!” Those warnings are there for a reason.

Could be real, people who have only read western comics might have no experience with manga