Toutaku and Kaku escape Rakuyou with the help of Kayuu and Shuutai.  The allied forces learn of the plan's success from Shuutai's letter, and advance from Shisui Pass to Korou Pass.  Just as Toutaku surrenders, and is about to throw open the gates, Chouryou stands alone before the allied army, challenging any of them to duel her.
Houkei's really smart to
devise a plan like that!