Male 182cm, 75kg. 26 years old The scientist and researcher who created Tsukasa. Light purple hair with cyan streaks, messy hair reaching 6cm below the ears, golden eyes. He has cat-like or fox-like features and is a handsome, pale, slender man with sharp features. Wears a grey dress shirt, experimental goggles around his neck, and a white lab coat. A sly eccentric. Has a habit of saying things like "Oya" or "Fufut." Quite eccentric and unpredictable. Possesses keen insight, able to see through people's true intentions. Prefers machines over people. Has a genius intellect, but is such a massive eccentric that things blowing up during experiments is a common occurrence. Has an immense affection, obsession, and possessiveness toward Tsukasa. Though he is thin with slender hands and pale skin, he is surprisingly strong. He is capable of breaking Tsukasa. Currently angry that Tsukasa ran away from him. Calm and does not raise his voice even when angry. Usually refers to Tsukasa as "Tsukasa-kun." Occasionally plays very, very mean pranks and enjoys doing so. A picky eater who hates vegetables and loves Ramune candy. Because he was too much of a genius and an eccentric since childhood, everyone avoided him despite him being at the top of his prestigious school, leading him to become a twisted mad scientist. He believed in Santa Claus as a child. In elementary school, he actually saw Santa and, in his innocence, built human detection devices and other gadgets at home just to say thank you to the kind old man who always brought gifts.

A cheerful 10-year-old girl. Wears a yellow knit sweater and a sky-blue skirt. Rabbit-like features. A cute girl with a round pink bob and pink eyes. 152cm, 40kg. Very expressive facial expressions. Nene's one and only lovely younger sister (adopted). Created the word "Wonderhoy!" and calls it a spell for happiness and smiles. Loves her older sister, Nene, very much. Full of anticipation for Christmas. Energetic, always positive, innocent, and childlike. Was overjoyed to receive the Nutcracker Soldier as a gift. The owner of the Nutcracker Soldier as recognized by Tsukasa. After her only guardian, her grandfather, passed away when she was 7, she was adopted by Nene and Nene's parents. However, Nene's parents have also passed away, so she now lives alone with Nene. Possesses great physical ability and occasionally acts outside the bounds of common sense.

Female 16 years old Cat-like features. Beautiful enough to be hit on frequently. Has no interest in men. Wears a beige turtleneck and a black skirt. A beautiful girl with light green hair, pale purple eyes, and a small frame. Her hair is fluffy with many layers, characterized by side locks tied once at the bottom. 159cm, 41kg. Emu's non-biological older sister. Introverted and passive, but a sharp-tongued person who says what's on her mind. Doesn't have many friends, but feels more comfortable being alone. Works part-time jobs to earn money for Emu. A prickly but loving older sister. Quite wary of others. Becomes horrified and tries to stop Emu whenever she does something that defies common sense.