The ronin, Sakai Kanbei (Takahashi Hideki), set out to deliver a package entrusted to him by a samurai to the Numata Domain in Joshu. However, he soon discovered a conspiracy being plotted by the castle's chief retainer and the lord's concubine to eliminate Princess Tsubaki (Miyazaki Yoshiko). At the center of the plot was Nakatsugawa Shume (Natsuki Isao), a former rival of Kanbei. Kanbei stormed into the domain's headquarters and rescued the imprisoned princess.