二天一流
, which can be loosely translated as "the school of the strategy of two heavens as one", is a koryū (ancient school), transmitting a style of classical Japanese swordsmanship conceived by the warrior Miyamoto Musashi. Hyōhō Niten Ichi-ryū is mainly known for the two-sword—katana and wakizashi—kenjutsu techniques Musashi called "Niten Ichi" (二天一, "two heavens as one") or "Nitō Ichi" (二刀一, "two swords as one").