Ok - I couldn't stay clear of these pages - so since there is mention of Kusanagi, and martial arts is kind of a thing with me - and the sword is my favorite weapon and the one I am working so hard on using right now, I have also been studying swordsmanship. So, here is a little more info on Kusanagi for those who might be curious:
The Kusanagi sword is the most legendary sword in Japanese history - and considering the Japanese affinity for and ties to swords, that is quite a statement. The sword was a gift from the gods (along with 2 other items - a mirror and a jewel) and the sword with those other 2 items became a symbol of the divinity of the emperor of Japan.
From another website detailing the history: Legend tells us that Susano-o, the god of storms and the sea, who had been exiled to Izumo, discovered the sword after rescuing a damsel in distress from a dragon. Susano-o saw a maiden who was about to be sacrificed to appease an angry eight-headed dragon named Yamato-no-Orochi. Susano-o gathered eight vats of rice wine, one for each of the dragons heads. The gluttonous dragon drank until he passed out at which point Susano-o hacked the beast to pieces with his own sword called variously Ama-no-Haye-Kiri (Fly-Cutter,) Worochi-no-Kara-sabi or Worochi-no-Ara-masa. As he was cutting through the tail he heard a clank and upon closer inspection discovered a sword hidden inside. Recognizing this as a sacred weapon he gave it to his sister Amaterasu, the sun goddess, who would later send it to earth and pass it on to her great grandson Jimmu-Tenno the first emperor of Japan as a symbol of his divinity.
The sword which was called Ame-no-Murakumo-no-Tsurugi "The Sword of Billowing Clouds", was kept in the Imperial palace until 92 B.C. when the 10th Emperor Sujin (97-30 B.C.) had the Kusanui Shrine built to house it and installed his daughter to care for the sword and the Mirror. Emperor Sujin was known to have had copies made of the three pieces of imperial regalia, a mirror, a jewel, and the sword, to remain in the shrine to hold the spirit of these treasures while the originals traveled with the emperor. In 5 B.C. the Kusanui Shrine was moved to Ise.
Generations later Prince Yamatotakero-no-Mikoto, the son of the 12th Emperor Keiko (71-130 A.D.) stopped at the shrine to pray on his way to fight the Ainu (Ebisu) people from (Tokaido) the north. The priestess Yamato-Hime, Prince Yamato's aunt had a premonition that if she lent him the sacred sword that he would be victorious. At one point in his battle Prince Yamato was surrounded in a field and the Ainu set fire to the grass hoping to burn the Prince out. Yamato drew the Billowing Clouds Sword and slashed through the tall grass creating a fire break. Just then a divine wind came and blew the fire back at the Ainu giving Prince Yamato the victory just as his aunt had foreseen. Prince Yamato returned the sacred sword to its shrine and from that day forward it was known as the Kusanagi or "Grass Cutting Sword".
In 668 A.D. a Korean monk [side note from dreamingofedward - this is an interesting date in Korean history and seems merely coincidental but it is the year in which Silla, with the support of China, conquered and subjugated Paekche and Koguryŏ and unified the 3 Korean kingdoms] named Dogio stole the Kusanagi and boarded a ship attempting to return home to Silla. As the ship set sail Susano-o, the god of storms, the sea, and self-appointed protector of the sword, whipped up a typhoon which forced the ship to turn back to Japan where the sword was recovered. Another version of the tale is that the monk threw the sword into the ocean to appease Susano-o, who then returned it to the shrine. In 686 the Kusanagai was moved to the Shrine at Atsuta after a divination revealed that the Emperor Temmu's illness was the result of a curse associated with the sword.
In 1185 at the Battle of Dan-no-Ura, the Taira clan representing Imperial rule and Minamoto clan representing the Shogunate were fighting for supremacy. The young emperor Antoku and his grandmother were on a ship surrounded by those of the enemy. Rather than allow themselves to be taken alive the grandmother grabbed the boy emperor and the two pieces of imperial regalia and leapt into the ocean to drown them both. An arrow tore her robe and she dropped the Mirror on board, but she took the sword and Antoku with her to the bottom of the straits.
The story takes different directions at this point. The Taira clan says that the sword was lost and because of this no subsequent emperor has been properly enthroned.
However the Minamoto claim that the young emperor was only carrying the replica and the original was still safe in the Atsuta Daijingu Shrine in Owari.
Another version of the tale says that Susano sent water birds to dive for the missing sword and after recovering it they returned it to the shrine at Atsuta for safe keeping.
There is more... about a curse and everything. But this is some interesting background information for those that might be interested.