Katanas are forged to have the hardest, and therefore keenest, edge of all swords, and they can slice through objects few other swords can, like tree trunks and machine gun barrels.
So what challenge can an egg possibly present to the sharpest of all swords? The challenge of cutting the egg's delicate shell in half rather than cracking it into a million pieces.
The Crazy Russian Hacker teamed up with YouTube channel Zombie Go Boom to shot this slow motion footage of a katana slicing through raw eggs like butter, do with this footage what you will!
-Via Laughing Squid
Only in movies.
http://fioredeiliberi.org/
For a comprehensive breakdown on what katanas can and cannot do see the following list of short videos:
https://www.youtube.com/playlist?list=PLMUtS78ZxryO9NKU_ceM-LhcnSnAc2kHV