The Ittou-ryu had its members slaughtered by the shogunate. Kagehisa gathers the remaining members of Ittou-ryu in secrecy, and plots revenge against the shogunate. Manji is invited to the Mugai-ryu by Giichi, but he refuses, and they clash swords. Giichi's weapon breaks, so a truce is called. Manji decides to go meet the head of the Mugai-ryu, Habaki.

Ever since the Dewanosuke incident, Burando kept making blunders. He is finally thrown in solitary confinement by Habaki, and goes insane. But as a result of his madness, Burando grasps something important about the immortality experiments: That humans are essentially otters. Meanwhile, Rin and Doua resolve to infiltrate Edo Castle to rescue the surrounded Manji and Isaku.

The Ittour-ryu are pursued by the Rokki-dan, lead by Habaki. Upon hearing this, Run and Manji decide to pursue as well. Even with all these people leaving Edo to chase the Ittou-ryu, the four leasers appointed by Kagehisa Anotsu are nowhere to be found. Then, in the wee hours of the morning, Kagehisa and the other three stand at the Ootemon in front of Edo Castle.

Rin and Manji chase after Kagehisa, but Shira attacks them and Rin is taken away. Manji goes to rescue her, and meets not only Shinra, but Renzou as well. Manji fights Shinra in order to rescue Rin. But astoundingly, what slashes at Manji is Shira's left arm, which should have been lost.