Tendoki

 is a pair of swords created by one of the top blacksmiths in Konohagakure. The swords themselves are constructed of the sword hardest substance as known the Diamond. As such, the swords are nearly indestructible and can it through anything they come into contact with. These swords were handed down from the blacksmith to Senjō before his passing. And with his death, he took the secret of diamond swords with him.