Chapter 46 of Hell's Paradise: Jigokuraku.
While sailing off to Kotaku, Aoki finds that the shogun was foolish in planning to send off multiple Iwagakure ninja and believes that their leader has motives of his own. Shugen comes to talk to Aoki thinking that he is concern with the ninja on board and offers to correct this. Aoki questions if him and the three Asaemon were capable of fighting all of them and becomes concern with the two Asaemon that are unranked. Shugen vouch for their qualifications, along with adding that Jikka was barley qualified. Kiyomaru becomes annoyed with Aoki not thinking he was strong and offers to demonstrate his skills to him. Isuzu tries to stop him but Kiyomaru draws his attention to one of the ninja and cuts the mask off the ninja next to the former. Isuzu gets furious with Kiyomaru's rude behavior and draws her blade near his neck demanding that he sheathes his sword. The two then exchange cold glares at each other. She apologies to the male ninja but assures her that he did not mind since they are all dedicated and loyal to the Yamada while on the mission. Kiyomaru tests his loyalty by having the ninja kill himself. Before following the order, the male ninja passes on the leadership to the ninja next to him and stabs his neck with his sword. At that moment, one of the Iwa ninjas remembers their orders given to them by the Iwagakure Chief to kill Gabimaru even if it cost them their lives. Kiyomaru discusses with Shugen if they can trust them. Shugen explains that he never trusted them since he sees them no better than criminals and states his resolve to have every criminal on the island executed so that his clan members can return home. After Kiyomaru asked the possibility of them being killed, Shugen becomes angry and causes Kiyomaru to be frighten or his aura. Shugen then hopes that Eizen and the others are alive. Meanwhile, Jikka questions Aoki if bring more reinforcements was going to make the mission more difficult. He explains that the shogun plans to make a swift resolution and thinks that the vanguard will be overjoyed by their upcoming arrival. However, Jikka informs him that their arrival is meant to bring more catastrophe than being reinforcements. With this in mind Jikka tries to persuade him into having ship return home.