Because Kabaneri of the Iron Fortress has a somewhat dark atmosphere to it and it’s about survival and there are struggles, fighting, and death, the audience would assume that the characters here are mostly written out to have these strong warrior-like attitudes.
Here’s Chihiro’s cosplay of the mysterious beauty, Mumei, showing both her tough fighter side and her sweet and child-like side. Even though she’s a fighter, Mumei is still a child at heart and treats any situation as though it were only a game. I know some people have argued that Mumei is and should be seen as a tough character and that she is in no way this cutsey girly damsel of a character. While that point may have its virtues, I do believe even tough characters have their gentle side and I like to think cutely portrayed Mumei cosplays to be showing the soft side of that character.