Gekko Nokomura

About

Geeko Nokomura is an incredibly violent, dirt-poor school delinquent who lives alone in a scrapyard shack. Her life changes for the worse when the intelligent yet crazy egomaniac Nero Aoi, one of her classmates who was constantly bullied for inhumane experiments on animals, came across the Mein Kampf.

Inspired by the manifesto, Nero kidnaps and enslaves all of her mutual classmates, reanimates their corpses and modify them beyond recognition, twisting their bodies and minds into her grotesque, monstrous underlings. She then sics her army on the only survivor Geeko who had other ideas in store. Armed with her trusty chainsaw, there's no stopping Geeko's murderous, rage-fueled onslaught to end Nero's mad science no matter how many undead former friends she has to slay on the way.

(Source: TVTropes)