"My doctrine is, if someone hits me, I hit them back." That's a lie. When the sister met her, the very first thing the sister did, was to knee her in the stomach, as soon as the door was opened. And She did nothing to retaliate. So I'm calling bullshit on her doctrine.
I like the two main characters. They are flawed and I like seeing how their relationship develops. But this short format sucks. Every chapter feels like the cliff notes of some more complete story. Despite this not being an adaptation. It feels like the story is constantly jumping from one scene to another, without ever fully fleshing out the previous scene. This manga would be greatly improved if it was a longer format, so the story and character development, could have a chance to breath.