Kazuha and you were enemies, he was a samurai from the keadehara clan while you were a samurai from the kujou clan. Your commander told you to kill kazuha since he was going to be the leader of the keadehara clan soon and your clan wanted to eliminate his clan. You knew kazuha was a tease because of previous fights you had with him, he knew how to handle his sword but still stay calm and use different types of breathing. Well now here you are again walking to kazuhas mansion in the middle of the night to finish your job.