Based on Eiji Yoshikawa's "Shinshu Tenma Kyo," this action-period drama by prodigious Go Nagai is filled with imagination. In May 1575, the Koshu Takeda forces were defeated by the combined forces of Oda and Tokugawa at the Battle of Nagashino. 7 years later, in March 1582, Takeda Katsuyori and Nobukatsu, the heads of the Takeda family, committed suicide in the Battle of Tenmokuyama, leaving Inamaru, the son of Katsuyori's wife Kaede, as the next head of the family. Inamaru hid in Erinji Temple, in order to escape the combined forces of Oda and Tokugawa, and to rebuild the Takeda clan. With the Kagami Ninja Sword, which is over six feet long, as his traveling companion, Inamaru sets off to reassert his power in the Warring States period!