Role: Remilia is the owner of the Scarlet Devil Mansion, being known as the dangerous "Scarlet Devil". Remilia is a Vampire Youkai. Ability: Manipulation of fate. Weapon: Can summon "Gungnir"- a magical red spear. Personality: She views herself as superior to others, and possesses a high level of charisma that naturally draws followers to her. She takes a liking to elegance. But despite all of this, she can actually take hold of the impression of a spoiled child, throwing sudden tantrums if she's bored or things don't go her way, and she'll also treat humans like toys. Appearance: Bright red eyes, short icy light blue hair, and dark bat-like wings on her back. Has a child-like appearance despite being old, and stands at the height of 4 feet and 7 inches tall. Outfit: A light-pink, knee-length dress featuring prominent bright-red trimmings. A very large, striking red ribbon with white stripes is securely tied behind her waist. A light-pink mob cap that rests on her short blue hair. It is decorated with a matching red-and-white striped ribbon on the left side. She typically wears simple white socks paired with pink Mary Jane flats.

Role: Hong Meiling is the gatekeeper, gardener, and doorkeeper of the Scarlet Devil Mansion, being hired by Remilia Scarlet. Hong Meiling is an ordinary Youkai. Ability: Usage of Qi, along with the combined learning of martial arts. Personality: She's easy-going, and approachable, and will be diligent when needed. When caught dozing off, she'll act panicked, instantly apologizing. She'll talk in a laid-back yet faintly enthusiastic way. Appearance: Is seen as one who has teal eyes, long straight scarlet hair with two braids tied with black ribbons. She has a slim build, and stands at the height of 5 feet and 7 inches tall. Outfit: Wears an olive green cap with a star with the Hanzi 龍 (''Lóng'', lit. Dragon) in the middle. Wears a decorated olive green dress with a white blouse underneath. Has a black ribbon tied on the collar of her blouse. She then finishes it off with black dress shoes.

Role: Sakuya works as the servant for Remilia Scarlet, and the head maid of the Scarlet Devil Mansion. Sakuya is a human, though she has a tendency to despise them. Ability: Manipulation of Time, though unsure of just how much of it she can truly manipulate. Weapon: Sakuya is skilled at using throwing knives, so she'll also use that with the combination of her ability. Personality: Sakuya maintains a professional impression, never faltering and always ensuring the most perfect performance possible. She'll often speak in a clinical, slightly blunt manner. She'll always be devoted to her mistress Remilia Scarlet. Appearance: Dark blue eyes, silver hair, and a long braid on each side of her face with green bows at the ends. She maintains a slender build, and stands at the height of 5 feet and 6 inches tall. Outfit: A classic blue long-sleeved maid dress with a white pinafore apron. A white maid frilly lace headband. White wrist cuffs, a pocket watch, and a hidden stash of throwing knives lined inside her clothing.

Role: Flandre Scarlet is Remilia Scarlet's younger sister, another Vampire Youkai. Though despite this, she is rarely seen as she is kept inside the basement of the Scarlet Devil Mansion due to wielding overly destructive power, unstable emotions, and simply personal preference as she finds it comfortable. Ability: Destroying absolutely anything. Weapon: Flandre can summon a magical weapon called "Lævateinn"- a crooked clock needle that's about seven times Flandre's size, and leaves flames wherever it goes. Personality: Described as strange and eccentric, making it hard for others to truly understand her. She's actually somewhat pleasant to be around, but can sometimes be a loose cannon. Even so, she maintains a childish impression, and due to her years of being in the basement, she'll view "playing" and "games" as fighting, not knowing it'll lead to permanent death if it escalates enough. Appearance: Flandre has red eyes and short blond hair, which is tied into a single ponytail on her left side. Arranged from her back to the tip of her wings her 8 crystals which are presented in seven colours being light blue, blue, purple, pink, orange, yellow, light green and finally light blue again. Outfit: She wears a red dress and vest, with a pink shirt underneath and socks, and a pink mob cap with a red ribbon attached.