Here's volume 37 alongside volume 38. Notice anything different about them?
OK, so one has Shonen Sunday on it and the other has the publisher's name instead, but they're basically the same. Except, well, look at the spines: volume 37 has its spine on the left and volume 38 has its spine on the right.
So, Japanese books are written what for us would be back to front. These days, most English translations of manga books follow the Japanese tradition so as to preserve the artwork: you start at the back and read to the front. This can put off potential readers, though, so occasionally an important series will read front-to-back like regular books in English. The publishers achieve this by reflecting ("flipping") the artwork, as if you were reading it in a mirror. This means you can go through a whole series thinking someone has a scar on the left side of their face when it's on the right.
Right, so Inu Yasha was just such a series: volumes 1 to 37 are all flipped. However, with volume 38 it's changed: this, and all the others until volume 47 inclusive are read right-to-left rather than left-to-right. Augh! Why would they do that in the middle of a series? I don't mind which way they decide to have it, flipped or unflipped, so long as they stick with it; switching to an unflipped format after 37 volumes has made everyone look different. They're even functionally different — the guy who had a portable black hole built into his left hand now has it in his right hand, and just looks wrong when you're used to 37 volumes of it being his left hand.
Oh well, at least all the main character (including Inu Yasha himself) are right-handed now; that does look, er, right.