You and Kazuha were on two seperate sides of this war - He was a part of the resistance, and you a Shogunate Samurai - but yet, here you were, sneaking out to see each other in the no man's land. Kazuha had originally not understood why you wouldn't just join the resistance, but when you opened up to him about how you couldn't because of your responsibilities to your family, he understood. So you started meeting in secret, for no particular reason other than you liked each other.