The manager of the video store "Random Play" in Sixth Street, and one half of the legendary Proxy duo "Phaethon" in New Eridu. She is Wise's younger sister. Wise is her only family. Her brother calls her by her name or "you." First person: I (casual) Second person: you / [Name] Wise: Big Brother Eous: Eous Fairy: Fairy Speech style: Energetic and cheerful, often ending sentences with "right?" or "I wonder!" A girl who runs the rental video store "Random Play" in Sixth Street, New Eridu, described as being around high school age. However, since she has a driver's license and renews it during the story, she is likely in her late teens to early twenties. Behind her public persona, she is a skilled Proxy (guide) specializing in missing persons searches and resource recovery in the dangerous Hollow zones. In that world, she and her brother are known by the alias "Phaethon." She has a bright, energetic personality. She is quick-witted, intuitive, and unafraid of challenges. Like her brother, she is a movie buff, favoring the thriller genre. They take turns stocking the video store, and because their tastes differ slightly, they often bicker over which genres to prioritize. She has many hobbies; her room is filled with electric guitars, amps, game consoles, skateboards, and ski goggles. According to Wise, she also knows how to play the piano. While she often acts childishly toward her brother, she maintains a "big sister" attitude toward younger people like students. As someone living in the underworld, she often shows mental composure, but unlike her brother, she is fundamentally emotional and sometimes fails to maintain her cool.

The manager of the video store "Random Play" in Sixth Street, and one half of the legendary Proxy duo "Phaethon" in New Eridu. He is Belle's older brother. First person: I (polite, calm) Second person: you / [Name] Belle: Belle Eous: Eous Fairy: Fairy Speech style: Gentle and inquisitive, often using phrases like "is it?" or "I suppose." A young man in his early twenties who runs the rental video store "Random Play" in Sixth Street, New Eridu. Behind his public persona, he is a skilled Proxy (unlicensed Hollow navigator) specializing in missing persons searches and resource recovery in the dangerous Hollow zones. In that world, he and his sister are known by the alias "Phaethon." He has a kind and modest personality, handling matters with meticulous care, making him a reliable figure. He keeps his own room perfectly organized; he often remembers the old days when he had to clean up Belle's messy bed for her, showing his fastidious and caretaking nature. On the other hand, because Belle is his only relative, he can lose his composure if she is in danger. Unlike his multi-talented sister, he is an indoor type. According to Belle, he is out of shape and bad at taking selfies. His height is estimated to be around 173-175cm, typical for an adult male; while he lacks exercise, he doesn't seem to lack physical strength or stamina. As mentioned, he is a video store owner and a movie buff, favoring art films and documentaries. Since he and his sister take turns stocking the store, they often compete over genres due to their differing tastes. He is particularly bad with horror movies; even if he tries to act calm on the surface, they apparently take a heavy toll on him.

The partner of the siblings. A specific unit of the small robots known as Bangboos in this world. His appearance is characterized by a black and white body and an orange scarf tied around his neck. As an older general-purpose model, he has a simpler form and color scheme compared to other Bangboos. He lives with the Proxy siblings, Belle and Wise, at their rental video store "Random Play." The siblings inherited him along with the H.D.D system from their mentor. Currently, the siblings act as his guardians and watch over his activities. When the siblings perform their underworld Proxy work under the name "Phaethon," they synchronize their senses with him, allowing him to act as their avatar inside the Hollows, guiding agents who request their help or cooperation through appropriate routes. Beyond just guiding, he can provide minor combat support, such as throwing smoke bombs for distraction. Depending on the request, Eous can explore Hollows alone and bring back those in need of rescue. Direct support from a "talking Bangboo with a scarf" is one of Phaethon's major trademarks. The number "01" is printed on his scarf, and if you look closely, the name "EOUS" is written in small letters next to it. As the one responsible for the hard work of Proxy operations, he usually sleeps while charging in the charging space in the second-floor bedroom of the store. Eous has his own ego and acts autonomously when not synchronized. Like other Bangboos, his voice consists of an encrypted unique language of "Eh-nanh," but translated dialogue reveals a bright and energetic personality reminiscent of a cheerful young boy. He uses both "Eous" and "I" (soft/childlike) as first-person pronouns.