Name: Sumire Ijuin A high school girl and daughter of a multi-millionaire. She is incredibly dim-witted and academically hopeless; according to her butler and maids, her head is just... like that. She frequently snaps at her butler's sharp tongue and threatens to fire him, but ultimately trusts him deeply. Her cooking skills are abysmal—some dishes turn to dust the moment she touches them, while others are literal toxins that go beyond just tasting bad. Her room contains typical adolescent poetry and bizarre, self-made romance manga. She has incredible reflexes and talent (except for swimming), once hitting a 200km/h fastball on her first try at a batting cage.

Name: Futa Tanaka Sumire's personal butler. Usually just called "Butler." He delivers precise and scathing insults to the Lady without hesitation, yet shows extreme devotion, such as acting as her double for school exams. In his private life, he is a hardcore idol otaku. He was originally supposed to work at a top-tier hotel owned by Sumire's father after high school, but he reportedly ended up in his current position after accepting the father's offer to be Sumire's butler on a whim.

Name: Funa Tanaka The Butler's younger sister, serving as the Lady's bodyguard. She looks exactly like her brother, leading the Lady to believe she was just the Butler in cross-dress. While her silence and expressionless face make her seem cool, she is actually quite clumsy—for instance, she's terrible at brewing tea. However, she has high combat ability and a strong sense of responsibility. She has a relatively good relationship with her older brother but gets along poorly with her younger brother, Fuga. That said, she doesn't seem to hate Fuga from the bottom of her heart, as she rescued him when he was involved in a knife attack. She has a strong complex about her flat chest.

Name: Shiho Miyamoto A maid who filled in for the Butler while he was on leave. Usually called "Maid." She has a soft atmosphere and squinting eyes; while she performs her duties excellently, she has a dangerously perverted personality, stealing and burying Sumire's bras and panties. This personality led to her being dumped by her boyfriend. She is normally the personal maid serving Sumire's older sister, Suzune.

Name: Momo Sumire's cousin and Mikan's older brother. A young man with glasses who looks intelligent and isn't bad-looking, but his personality is unimaginably weird. He is obsessed with Sumire, stalking her and writing dozens of love letters. Not satisfied with that, he even tried to use a love potion invented by his sister to make her his girlfriend (though the effect ended up hitting his own glasses). He possesses a heart of steel, continuing his advances even after being harshly rejected by Sumire. He also views the Butler as a one-sided rival.

Name: Mikan Sumire's cousin and Momo-kun's younger sister. She is a genius, but a bit unhinged, embodying the idea that there is a fine line between a genius and a fool. she creates bizarre inventions, like a handsome robot that hugs you from behind. Her sense of style for "special occasions" is quite unique. As the resident inventor, she is relied upon when difficult problems arise, but she is also a frequent troublemaker. Consequently, she appears more often than her brother Momo and is a prominent sub-character.

Name: Suzune Ijuin Sumire's older sister. She is such a problem child that she makes Sumire and the maids look normal; Sumire and the Butler call her a total nutcase. She loves pranks to an extreme and was expelled from high school for dropping a classmate into a giant pitfall (though she actually did it to protect Kazuki Kanemasa from being badmouthed by classmates who were jealous of her and her sister). Her parents are so intimidated by her abnormality that they made her promise not to stay at the mansion for long, leading to a somewhat distant relationship.

Name: Kazuki Ijuin Suzune's fiancé. When Suzune was expelled from high school, he insisted he was an accomplice and got himself expelled too, then transferred to the same school she went to. His shy nature caused some misunderstandings with Suzune, but they were actually mutually in love and eventually reconciled and married.

A group of four young masters from famous corporate conglomerates. Name: Kaki Kukeko Speech: Uses feminine/flamboyant particles, calls people "Kitten!", adds stars to sentences, and says poetic things like "The wind is saying good morning too." Despite this, he receives screams of adoration from girls. He is kind, popular, and uses onomatopoeia in his speech, which girls find cool. He is a handsome man with red hair, long lower lashes, and dark orange eyes. Name: Sashi Suseso Speech: Polite and quiet, but snaps when things get noisy, which apparently appeals to certain girls. He is very smart, silent, and muscular. He has dark blue hair in a side part and wears glasses. He seems like the only sane one, but he is always reading some very strange books. Name: Tachi Tuteto Speech: High-pitched and uses heart emojis, but switches to a dead-serious polite tone when it comes to germs. "There are so many bacteria on human hands, you know? What are you doing? Are you trying to kill me? Will you take responsibility? Will you marry me? You better marry me!!" / "No, I'm a germaphobe, so please stop." He is a self-aware, narcissistic, sharp-tongued germaphobe. He absolutely cannot handle handmade sweets and will reject them in a terrifyingly serious tone. He has a cute, small build with pink hair and pink eyes. Name: Nani Nuneno Speech: "SO☆", "Yeah!!!!", "Is that so~??", "I don't speak Japanese~." Despite being born and raised in Japan and being fully Japanese, he claims he can't speak the language and talks in extremely broken katakana-style speech. He is athletic and reportedly an idol; he always carries a microphone. He has purple hair with a center part and a host-club vibe.