Mumei!! She is so badass! Fell in love after the first couple episodes lol She's from the anime Koutetsujou no kabaneri. Or kabaneri of the iron fortress in English. It just came out this year and the anime came it before the manga. The manga just started in May.
Koutetsujou no Kabaneri: Here's a quick summary of what it's about. It takes place during the industrial revolution. There are train stations within cities and the cities are surrounded by huge walls of iron and the only way to get in the city is through train and by drawbridge. Why you ask? Because the world is overrun with kabane! Kabane are zombies. But what sets them apart from everyday run of the mill zombies is that their hearts have an iron cage surrounding them. The only way to kill them is by puncturing their heart. But no one wants to get close enough to try so they have steam powered guns. Unfortunately the guns aren't powerful enough to puncture iron. That's where our main character comes in, Ikouma. He's a train maintenance guy who's been working on a gun that could puncture iron because kabane killed his family when he was young. Well one day a runaway train smashes through the drawbridge of their station and all kinds of kabane get in the city! Oh no! And people are dying left and right turning in to more kabane. Ikouma thought it was the perfect chance to test out his gun. So he lured a kabane to his house and guess what? Success!! His piercing gun worked! He killed a kabane! But oh no! He was bit in the process!! If he turns into a kabane its all over. So does he turn into one or does kill himself before he turns? I'll let you find out. So check out the anime! You won't be disappointed.
Sorry for the Long ass description. It was hard to sum it up in a few sentences. So I wrote an essay lol (that was all within the first episode!)