It was difficult to infiltrate the castle of the rival clan, but thanks to a grappling hook, Kazuma infiltrated the fortress (risking to die by falling because of old and presumably of poor-quality mortar). Once inside, Kazuma thought about how to killing his enemies in silence and without being seen. This goes against the bushidō (武士道, the way of the warrior), and Kazuma... well, Kazuma knows it well, but these killers have no honor, and it's good that Kazuma's here to stop them.
