Kosho

Kosho takes the form of a katana and holds a place within the Skillful tier, a group of fifty renowned blades. For a period, it served as the property of Trafalgar Law. What the weapon actually looked like remains largely a mystery, because the artwork revealed nothing beyond its grip, though that grip followed the plain build typical of a katana's tsuka. Its earliest showing arrives within the first chapter of Law: The Hour of Kikoku, a spin-off novel, and that same installment is where the sword meets its end.

Belonging to the Skillful tier gave the katana genuine cutting strength. On one occasion Law felled a group of twenty pirates using nothing more than a lone stroke. He also matched the blade against the oversized axe carried by Kalik Meidara and managed to fend the attack off, yet the effort broke the steel, and it snapped apart during that exchange.

Law came to own the katana at some stage over the prior ten years, since he had departed Swallow Island a decade before without yet holding it. Throughout the Kikoku novel he treated the weapon as his go-to armament, defeating Kalik Meidara with it right up to the moment the blade cracked. Plunging into the water once the fight ended, he watched the shattered piece drop away and disappear beneath the surface. He chose to keep the remaining grip inside his room, treating it as evidence of how far he still fell short, and once he had spent a stretch of time on Welbems Island, he interred the hilt in the garden belonging to Hakugan's home, fashioning a modest grave for it.