Kana Arima as a young child is introduced as a former prodigy whose early career was marked by both remarkable talent and a difficult personality. From a very young age, she was a nationally recognized child actress, famously known as the kid who could cry on command in ten seconds. This technical skill, combined with a natural, sun-like charisma that drew all attention to herself, made her a household name. Her acting style during this period is described as selfish and self-centered, as her performances were so powerful that they would unintentionally outshine her co-stars. This led to her developing a pompous and imperious attitude, making her difficult to work with even as her talent was celebrated.

Her background in the industry was shaped by the adults around her, who treated her as a commodity. As she grew older and her child-like charm began to fade, her arrogance caused job offers to dry up, plunging her career into a "dark ages" period. Her mother began pressuring her, and she grew desperate, trying various fields like singing to stay relevant. One notable success from this era was the children's song Green Pepper Exercise, which reached number one on the Oricon charts, a past she would later come to regret. This early success followed by rapid decline instilled in her deep-seated self-esteem issues that would persist into her teenage years.

A key moment in her young life was meeting Aqua Hoshino on a film set. After witnessing his performance, which was more aligned with the director's intentions than her own technically perfect acting, she was moved to tears and recognized a significant gap in their abilities. This experience humbled her and left a lasting impression, making her intensely aware of him as a rival and peer. Her relationship with the producer Kaburagi Katsuya also began in these years; he would continue to employ her not necessarily for her star power, but because she was considered low-cost and easy to handle.

The pressures of her decline forced a major change in her approach. To survive in the entertainment industry, she consciously evolved her acting style. Where she once sought to dominate every scene, she learned to become more adaptive and supportive, focusing on elevating her co-stars and making herself easier to work with. This ability to adjust and her strong sense of responsibility became defining traits, even as they stemmed from a place of insecurity. Her primary motivation shifted from showcasing her own brilliance to simply keeping herself employed and proving her worth, a silent cry for someone to finally acknowledge her efforts.