Ha ha ha... There are all manner of ways to name your sword.

It may be something that comes to mind when you gaze upon it - after all, I am named Mikazuki after the crescent moons that line my blade. My companion, Kogitsunemaru, is named after the fox spirit that helped our smith forge him.

Others still are named after tales of what they have cut - Onikiri, for the sword that slain countless demons. Tonbokiri, for a spear so sharp that when a dragonfly laid upon its blade, it was cut clear in two.

Adding your own last name to your sword is a common practice... says I, who was forged by none other than Sanjou Munechika.