Yeah, Jonathan, that is what Masa/Mune said.
Someone mentioned that Masa and Mune were out of the sword in Ocean palace- they're out of the sword in Denadoro Mts. too. If they were created to aid in the destruction of the MM but not bound to the sword as such then maybe the MM bound them to the sword, creating the Masamune? But, anyway.
I also agree with Jonathan that it was considered legendary due to it being so hard to acquire.
On a slightly related note, I have heard that some people believe that Dalton stole the Masamune and destroyed Guardia- what are the reasons for this? And also, do Masa and Mune only possess the power to stop the Masamune from being retrieved from the stone, or do you think that they can stop it being used? Because in all honesty if they possessed the power to stop a person from using the blade, why would they let an asshole like Dalton near it?
Sorry if this is considered unrelated but it is to do with the Masamune.