Kusanagi is a Rank A sword fused from Cloud Stone.
|Fused from 3||Sword of the Clouds|
|Fusion Time||28 Hours|
|Attack Points (AP)||42|
|Defense Points (DP)||28|
"Kusanagi-no-Tsurugi (草薙の剣?) is a legendary Japanese sword and one of three Imperial Regalia of Japan. It was originally called Ame-no-Murakumo-no-Tsurugi (天叢雲剣?, "Sword of the Gathering Clouds of Heaven") but its name was later changed to the more popular Kusanagi-no-Tsurugi ("Grass Cutting Sword")."
This excerpt was taken from the Kusanagi Wiki page. For more information on Kusanagi, click here.
It seems as if there is a kind of temple in protecting the sword as there are paper with writing on it similar to an Ofuda which is a type of protection talisman.