Board Thread:General Discussion/@comment-1255374-20150613052507/@comment-995426-20150811132950

Good eye.

At the same time, I'm rather reluctant to call it an easter egg, since I know how much the series likes to recycle existing 3D model assets. For instance, the curtain's in Murakami's restaurant are the same as the lair kitchen's room divider, only palette-swapped to red instead of blue.

I'd more comfortably call that an easter egg if we looked at every other katana in the series not used by the Shredder, and examine to see if any of them are the same model.