Yet again more sad comments taking the manga and what the MC says WAAAY too seriously. The premise of this manga alone should tell you it's not meant to be a thought provoking story to be taken seriously. It's a deranged Harem, Comedy, Power Fantasy, detached from reality, and it's honestly...
Man most of these comments and essay length debates are garbage. Let ho's be ho's and make bread. It's a fictional story about fictional characters, MOVE ON!!!
Koko is just like Kanan, they are both older sisters that portray themselves as tough, but are weak against romance and the lewd. They'll get along just fine.