Chiko is a sickly human girl living in a heavily polluted city. Her health issues stem directly from the emissions of a nearby factory. This pollution shrouds the entire sky in perpetual gloom, creating an oppressive and unhealthy environment that worsens her condition, leaving her physically weakened. When Unico arrives, encountering Chiko forms the story's central relationship. Unico becomes determined to improve her situation, focusing on cheering her up and alleviating her suffering. This resolve drives Unico to confront the source of her illness, ultimately leading to the destruction of the nearby factory responsible for the pollution affecting Chiko. The documented information describes Chiko solely within the context of the "Unico: Short Story" movie narrative. This narrative confines Chiko's character development exclusively to this single film.