this should help with the confussion
and im guessing the little shit was calling her dear sister coz if his brother married her sister they would be brothers in-laws?
@ShinSekai what are u on about?. that was just a human reaction, his friend was gonna surrender herself to the enemy, and he just said ''hey, wait!'', he didnt think about fighting them right there it was just a shout coz shit was moving way too fast and he needed a second, and then everyone...