Shizuku Hasei serves as the personal maid to Aya Rindo, a role bound by a multi-generational family tradition originating in the Genna era. Raised from birth specifically for this duty, her lineage dictates her life's purpose. She exhibits a reserved and taciturn demeanor, consistently maintaining formal speech and composure. This stoicism sharply contrasts with her pronounced hostility towards Tsugaru Shinuchi, whom she treats with consistent disdain and readily employs violence against, often at Aya’s direct command. Shizuku's loyalty to Aya is absolute, forming the core of her motivations. This devotion manifests as fierce protectiveness, swift obedience to Aya’s orders, and an implied deeper emotional attachment extending beyond mere servitude. Physically, Shizuku possesses dark hair styled in a bob cut, longer in the front, and sharp, focused eyes. Her standard attire is a traditional maid uniform, though she has also been depicted in a nightdress. In combat, Shizuku wields the specialized bayoneted rifle "Tachikage," modeled after a Spenser 1865 Carbine. This weapon enables versatile engagement at firearm, mid, and close ranges, the latter often employing bayonet techniques reminiscent of naginata usage. Despite being fully human, she demonstrates exceptional martial prowess capable of confronting supernatural entities like vampires, earning classifications such as Ninja Maid and Badass Normal. Her fighting style remains pragmatic and efficient. Shizuku stands as the sole survivor among Aya’s retainers from the attack that resulted in Aya’s decapitation and the theft of her body. This event solidified her role as Aya’s primary protector and companion during their subsequent travels across Europe. Her purpose aligns with Aya’s quest: locating the assailant identified by an "M" on his cane and aiding in the recovery of Aya's stolen body. Notable moments include inadvertently exposing herself to the vampire Carmilla during combat in the Werewolf Village Arc due to Tsugaru’s failure to include underwear with her change of clothes. She also exhibits latent investigative aptitude, gathering crucial forensic details regarding Nora’s murder, though she relies on Aya for the full deductive analysis.