1616. High Priest Tenkai (Yoshida Yoshio) informs Yagyu Tajima-no-Kami (Konoe Jushiro) of his concerns about Hidenari, the surviving son of Toyotomi Hideyori who managed to escape from the Osaka fortress, and his mother, Katsura-no-miya Renko (Otani Naoko), who are in hiding following the impending death of Tokugawa Ieyasu. Reluctantly, Yagyu orders his subordinate Asahina Gen'emon (Sato Kei) to capture the mother and son, who are hiding in a temple in Kyoto. Although the mother and son manage to escape Kyoto's jurisdiction with the help of their maid Sasaka (Watanabe Yayoi), they are pursued by the Koga ninja, Yami no Shichibei (Toura Rokko), and the Iga ninja, Senri Unten (Watanabe Atsushi). On the beach, when Sasaka is about to be killed, she is rescued by the ronin casually present, Akizuki Rokurota (Tamura Masakazu). Rokurota's true identity is that of the Shogun's twin brother and successor, Tokugawa Iemitsu. Not being allowed a place in the Tokugawa family as a successor, he was sent as an adopted son from a young age and has been wandering alone ever since. Coincidentally, after saving the mother and son, Rokurota, drawn to Sasaka and together with Unten, who has betrayed the Tokugawa, decides to protect them both from assassins and travel with them.
