 Claims of ancient martial arts which survive unchanged by unbroken tradition (e.g.as suggested by Yehoshua Sofer), do not fall under reconstruction and are by their nature unverifiable, even to the person making the claim.Certain modern schools of Ninjutsu may fall under the category of martial arts reconstruction; the Bujinkan organization claims to base their teaching on a manuscript documenting a historical school, known as Togakure-ryū, dated to the 12th century.