Saika family made a name for itself by confusing the big troops of Nobunaga and Hideyoshi before, but, now in the 7th generation from Ineyasu's period, it was driven out into a deep mountain and had gone down in the world. A son of Ikkkokussai Saika (Takahiro Tamura), Sonshiro (DaisukeTaka) had run after a deer every day. One day, a man who seemed to be a Shugensya appeared in his place and ask him to assassinate Yoshimitsu of the Kishu Tokugawa family, who is a candidate for the next Shogun.