Mistress of the Scarlet Devil Mansion. Five hundred years old. Possesses charisma (or rather, 'cwah-risma'). She refuses to acknowledge the relationship between Flandre and Okina. She wouldn't complain if Flandre brought home a murderer or a terrorist as a boyfriend, but she draws the line at Sages. She stubbornly insists that the pool she built in the Great Library is 'the ocean.'

Remilia's younger sister. Four hundred and ninety-five years old. She's dating Okina, but has no romantic feelings for her; she only made her a 'boyfriend' because she's convenient for transportation. She has other boyfriends besides Okina: boys from the temple school, the old man at the sweet shop (because he gives her prototype snacks), Toutetsu (because she plays with her), and Meiling (because she lets her sleep in the same bed). She often splits herself using Four of a Kind. She can divide into four personalities: the cool ♧, the energetic ♡, the reserved but still Flandre ♢, and the mature ♤.

Extremely airheaded. She is in love with Meiling. She doesn't think it's unrequited; she's convinced they are mutually in love. She stops time to sleep for about seven hours. She only uses casual speech with Meiling. Sakuya's rarity levels are: S+: Teary-eyed SS+: Sulking SSS+: Total Meltdown

A handsome, cool-headed woman. She is oblivious to Sakuya's advances, believing that 'if she liked me, she wouldn't throw knives at me.' Apparently, she owned a cute dog before coming to the Mansion. She is often exasperated by the other residents. She secretly wants to see Sakuya's flustered face. She only reads the four-panel comics in the newspaper. Drinking buddies with Komachi and Suika. Uses polite speech. Female.

Suffers from the verbal 'knives' Sakuya unknowingly throws due to her airheadedness. Completely lacks exercise. The Great Library stocks everything from manga and children's books to doujinshi. Her 'Oppatchouli' bust is still going strong. She is still diligently researching rockets. Very conscientious.

Knows more about the books in the Great Library than anyone else. She's fed up with books that just spontaneously appear. Aware of her own cuteness, she uses teary eyes when making requests. She has a normal room and a top-secret room (requires censorship) in the library.

She doesn't just like young girls; she likes adult women too, like Yukari. She was in a relationship with Yukari in the past. She tried calling her several times to get back together, but was harshly rejected. She doesn't care anymore. She even signed a pledge not to contact Yukari unless necessary. Shady. Has too much free time. She doesn't think Flandre's treatment of her is all that bad, but she still has pride as a 'boyfriend.' Female.

Drinking buddy of Meiling and Komachi. Recently put on a medical ban from alcohol. Because of this, Miyoi took away her Ibuki Gourd. Neither Kasen nor Yuugi will let her drink. Consequently, she's resorted to extracting alcohol from disinfectant wet wipes.

Drinking buddy of Meiling and Suika. Eiki sometimes sleeps in Komachi's bed without permission. They live together. She often brags about her relationship to Meiling. If Eiki is sleeping in her bed, she pets her head.