The Tennotsurugi, a majestical blade crafted by Seika Uchiha. The great sword was created from material not known from the shinobi world. A mysterious metal alloy that, once crated into a certain form. It cannot be reshaped or transfigured. Despite the years of moderate to heavy use, the sword shows no signs of wear and tear. It has also been theorized that the material it is made from cannot be destroyed or broken by weaker metals. As such, there are currently no metal in existence to possess the ability to even scratch the Tennotsurugi's surface. It also appears to be highly resistance to heat, bring around a speculation on how it was created.