Chapter 56 of the Jigokuraku manga.
Summary[]
Before he agrees to engage in Bōchū Jutsu with Rien to understand his Tao, Chōbei demands that he tells him all about the island. Rien explains that the island is a laboratory meant to create and observe the creatures on the island that were made immortal, such as the tree people known as the Hōko. She then explains Tao and why she finds his Tao to be an important. Rien then further explains that after she completes her research in creating the perfect Tan, Lord Tensen will move on to the mainland and create more Tan from the humans. She then offers Chōbei a chance to join them if he cooperates. After thinking about his best course of action, Chōbei decides to cooperate with Rien. While engaging in Bōchū Jutsu, Chōbei hopes that Tōma waits for him to return. Later, while Gantetsusai becomes disappointed that Mei has reverted back to her child body, Shion prepares to announce the group's next plan. However, Mei senses that the the second landing party has arrived on the island but says that the Tao is either strong from many or strong from one person.