Machimaho: I Messed Up and Made the Wrong Person Into a Magical Girl! Vol. 13 by Souryu

A new enemy appears and she bears a striking resemblance to Rui, Kayo's best friend from childhood! Kayo is usually a stone-cold killer, but when she sees Rui again, her tough facade falters as painful memories come flooding back. Can Kayo face her past in order to survive the present?!
Binding: Paperback / softback