Sekki, the brother of Koshou, is the brains behind the Shisui rebels. When Youko appears searching for Enho, Koshou is about to attack her because he believes she is a spy who is going to give them away, but Sekki stops him. He later explains that he heard the ring of steel, and that Youko's bravery suggests that she is far more dangerous than she appears. Sekki makes all the tactical decisions for the rebels except when fire threatened Takuhou and Koshou overrides him.