The Masamune is the name of Sephiroth's sword (and it also crops up in other FF games in various guises), it's an extremely long, curved (having the sword slightly curved gives it more strength to witdthstand battles) sword. It could be a No-Dachi, a six-foot war sword. And probably originated from Japan's Old Sword Period (called Koto) which was their Golden Age of swordmaking. This was when they forged blades with a curve to make them stronger and they also made long swords which were over four feet in length (which Sephiroth's masamune certainly is >D). From reading in my martial arts encyclopedia (which is a very interesting book, btw +B) I have learned that "Mune" is the japanese name for the back of a sword, and there are all different kinds of classifications like "kakumune", "mitsu-mune", "mune-hikushi" etc. Which all mean different things about the backs of the sword, eg, mitsu-mune is a double back on a sword. 'Masamune' translates to 'straight back'/'straight backridge'. Anyway that's just a little bit about the Masamune and it's name literally. But most likely the name of Masamune comes from the Japanese swordsmith of the same name. One of the most (THE most?) reknowned Japanese swordsmiths of all time. Masamune lived during the Kamakura Era in Japan (late 1200s - early 1300s) and had an immense talent for sword-making. His swords were believed to have spiritual attributes to them, and some stories say only those with a pure soul could wield them. The famous legend behind Masamune's swords is this; if you placed the blade of a Masamune into a stream, if a leaf floated towards the blade, it would change course (as if being repelled by the sword's true nature) and not get sliced in two. The Murasame blade (interestingly enough, one of Cloud's swords in the game) in the same leaf test is said to attract any leaves that pass by and cut them all. This is because whoever forged the Murasame could not have understood properly the true purpose of a sword, to save lives not just to take. Hence the destructive nature of the sword. The Murasame appears to really be a legendary sword, probably based on the name "Muramasa" a swordsmith whose swords were cursed by his misunderstanding of his art (also interesting is that Muramasa was one of Masamune's pupils @_@;;). The Murasame was probably made up to contrast with Masamune's swords. Thankyou to everyone who has emailed be about the Masamune, and helped me clear through all the variations of information/stories/etc to [hopefully] get the facts right!