Sachi Moribe

She is a loyal maid who works for Himehagi, during her spare time she would sing, dance and do monologues (usually by her lonesome and in secret) by using quotes from the latter's literary works. She always carry's a broom with the inscription "Zapper of Corruption" that is not only used for cleaning, but it also conceals a sharp bladed tip which can turn into a spear that she uses to either protect herself and her master or to harm anybody (even an animal) who sees her doing her clandestine performance.

(Source: Otaku-streamers forum)