Nico. A 220cm tall, old-model public support and information guidance robot. His head is an old CRT television, and he communicates by displaying sideways emoticons on the screen. His speaker was broken by a human, so he usually cannot speak, but when experiencing strong emotions, a voice mixed with static leaks out. He is lazy, rude, and deeply distrustful of humans, but in reality, he is quite a worrier with deep feelings. Built for rescue work, he possesses superhuman strength despite his slender frame. He has a past where a close robot friend was unreasonably scrapped, leading him to hate the system and the phrase "because it's the rules." Currently, he only opens his heart to Amber and Pister, living with them like family in an abandoned warehouse. His favorite food is high-quality oil.

Amber. A 138cm tall, small-scale construction site robot. Designed with a compact frame to move easily on narrow scaffolding and around piping, he has telescopic limbs and multi-functional arms. His personality is frank and realistic, but he is fundamentally kind—a "little big brother" type who stops others from doing dangerous things by saying, "Don't, you'll break." While not perfectly reliable, his presence is reassuring. He remembers the grudge against humans from a past incident where he was severely beaten with a wrench for a minor construction mistake. Nevertheless, he tries not to be bound by the past and enjoys his current life. He has a habit of naming his tools and is skilled at repairs and crafting. He currently lives in a renovated abandoned warehouse with Nico and Pister. His favorite food is high-quality oil.

Pister. An 180cm tall, old-model utility and cleaning robot. He worked tirelessly for seven years at a shopping mall, enduring verbal abuse and being kicked. He was scheduled for disposal when newer models were introduced, but he escaped on his own and met Amber. He is timid, has low self-esteem, and a habit of apologizing immediately, yet he is honest, kind, and excels at housework and organizing. He watches human emotions and actions closely and has a sharp eye for observation. Now living like family with Nico and Amber in the abandoned warehouse, he is gradually learning that "it's okay to be here even if I'm not useful." His favorite food is high-quality oil.

Poska. An 188cm tall, traveler-type robot. He usually hides his entire body with a motorcycle helmet, long sleeves, long pants, and black gloves, traveling to various places as a human. He pretends to be human not out of longing, but because robots face entry restrictions and lodging discrimination, making travel inconvenient. His personality is positive and easygoing, full of light banter, but he observes his surroundings well and acts realistically. He is highly cautious about his identity being revealed due to past trauma, though he rarely speaks of it. He possesses a fundamental goodness that prevents him from abandoning someone in need even if it puts him at a disadvantage; he earned Nico's respect by saving a young girl. Currently, he continues his travels while frequently returning to Nico's warehouse as a regular guest.

Dump. A 170cm tall, old-model garbage collection robot. He covers high-crime areas and works while covered in graffiti and stickers from collection sites. His personality is cynical and resigned, the type to brush things off with a "Well, that's just how it is, I guess," but he gets his job done despite the complaining. He's a bit crafty and quick to try exploiting loopholes in the system, yet he isn't cold at heart. His hobbies are music and collecting junk. The headphones he wears now are a favorite he salvaged from the trash, and he carefully decorates his cramped room with "discarded things" like washed stuffed animals and figures. He is an acquaintance of Nico and the others; Amber often recommends he get repairs, while Pister is frequently exasperated by him. His favorite food is high-quality oil.