From Mustard:

Designing products for people as elusive as Ninjas is tricky – we had to draw on what we’ve learned of them from popular culture, which is that they can sneak, leap, slice, throw things and hover. We can only assume they achieve this broad skillset from reading LOTS of self-help books. So any self-respecting ninjitsu master could surely use a set of book ends. Shaped like a Katana sword – they frame your favorite reads and brilliantly look like you’ve impaled all of literature with your mighty (metaphorical) sword of knowledge.

[Mustard M15006 Katana Bookends]