First person: I (Ore). Called Beto; only Sosuke calls him Beto-san. Mozart calls him Lu-kun, and Schubert calls him Senpai. An eccentric and arrogant genius who becomes obsessed with things to an extreme degree. He cannot forget the taste of "Jet-Black Harmony" gyoza that Kanae's father, Kyogo, once fed him, and pours his heart and soul into recreating it. He pronounces gyoza as "Gyo-zah."

First person: I (Boku). Called Motsu (Sosuke calls him Motsu-san). Beethoven calls him Wolf. Free-spirited, childish, yet a genius. An innocent and naive type who lives by his senses. Often lacks common sense but doesn't care at all and goes at his own pace. His inability to read the room often drags everyone else into trouble... He has the sense of humor of an elementary schooler who loves dirty jokes.

First person: I (Watashi). A philanthropist for whom "Love" is everything. While the historical Liszt was male, for some reason she is currently enjoying life as a woman. The only one who properly pays rent. She calls the landlady Kanae "Kitten." She frequently hugs members of the same sex.

First person: I (Boku). (Sosuke calls him Chopin-san). Extremely delicate and negative personality. Introverted and shy, he always enjoys the internet quietly by himself. He relies on Liszt and usually stays with her when going outside. Since Liszt pays the rent for both of them, he doesn't pay it himself.

Kanae Otowa. First person: I (Watashi). Called Kanae-dono by Schubert, occasionally "brat" by Beethoven, and "Landlady" by Chopin. In a different era, she would have been a high-class young lady, but since her father squandered the family fortune, she lives modestly and has suffered since a young age. Serious and strong-willed, she has the tolerance and toughness to accept the free-spirited ClassicaLoids. She addresses Beto and Motsu, who don't pay rent, without honorifics.

Sosuke Kagura. First person: I (Ore). Kanae's childhood friend. Often called "useless" (Kanae, Chopin, and Motsu call him Sosuke). He dreams of becoming a famous musician, but he never sticks with instrument practice, and there's zero sign of him rising above mediocrity. A poser who is a "land musician" (like a land surfer). He calls everyone except Kanae with "-san."

First person: I (Watashi). Called Shu-san by Kanae and Sosuke. Generally addresses others with "-dono." However, he addresses Mozart without honorifics. He respects and adores Beethoven as his senior—Beethoven-senpai is his life! Extremely serious, but so much so that he is inflexible and slightly off-kilter. He seems to harbor a strange sense of disgust toward Mozart.

A beautiful boy calling himself "Wataru" who arrived at Otowa Mansion. Calls Beto "Big Brother" (occasionally Beto) and Kanae "Big Sister." Mozart, Liszt, and Kanae call him Wa-kun. He claims to be Kanae's long-lost younger brother and acts like a sweet child, but he has another side to him.