Soramaru's quest to grow stronger brings him to the leader of the Yamainu, Abe no Sousei. Sousei proposes a trade: training in exchange for information. In search of the information required, Soramaru disguises himself and -- with the help of youngest brother Chutaro -- infiltrates the very prison he's taken so many criminals to: Gokumonjo. But nothing is ever as easy as it seems, and although Soramaru finds the information he needs to make a deal, eldest Kumo brother Tenka suddenly finds himself under arrest and in dire straits...