Himeko Nonohara, often called Hime-chan, is the protagonist of her story. A spirited and energetic thirteen-year-old, she begins as a self-described tomboy who is more comfortable competing in sports than navigating the delicate world of romance and femininity. Despite her athletic prowess, she harbors a deep longing to be seen as a proper young lady, largely inspired by the grace and beauty she admires in her older sister, Aiko. This internal conflict between her natural, boisterous personality and her desire to be feminine is the central driving force of her early journey.

Himeko is characterized by her friendly, compassionate, and cheerful nature, though she can also be boastful and somewhat childlike in her actions. Her enthusiasm and determination are captured in her personal catchphrase, "Ike! Ike! Go! Go! Jump!" which she shouts when she needs a boost of courage or excitement. While her heart is usually in the right place, her impulsive decisions often lead to complicated situations, which she then tries to resolve using the magical tools at her disposal, sometimes only making the original problem more difficult to handle.

The course of her life changes dramatically when she meets Princess Erika from the Magical Kingdom, her exact double from a parallel world. For the purpose of Erika's royal test, Himeko is entrusted with a magical red ribbon that allows her to transform into any other person for exactly one hour. This new ability comes with strict rules and high stakes: the transformation must be reversed before time runs out, or she will be trapped in that form forever; she must never reveal the ribbon's secret; and she must perform the incantation in reverse to change back to herself. The ribbon also brings her beloved stuffed lion, Pokota, to life, who becomes her constant companion, advisor, and voice of reason.

While Himeko initially uses her powers in an attempt to win the affection of her older crush, Kouichi Hasekura, her role in the story soon expands beyond her own romantic desires. She often finds herself using the ribbon to help her friends and family, solve problems, and occasionally perform acts of justice, growing more adept and thoughtful with each challenge. Her relationships are the heart of her adventures. Her friendship with her two closest schoolmates, Manami and Ichiko, provides a stable and supportive foundation. Her admiration for her sister Aiko is a constant reminder of the kind of person she aspires to be.

The most pivotal relationship, however, is with the school troublemaker Daichi Kobayashi. After he accidentally discovers her secret, he becomes the sole person who knows about the ribbon, a position that breaks magical laws but is ultimately tolerated by the Magic Kingdom. What begins as a bickering rivalry slowly deepens into mutual trust and affection, and Himeko gradually realizes her childhood crush on Hasekura has been replaced by stronger, truer feelings for Daichi. Her journey is also complicated by her classmate Hikaru, who sees Himeko as a romantic rival for Daichi's attention and constantly suspects her of hiding something, though she never fully uncovers the truth.

Over time, Himeko gains additional magical abilities beyond simple transformation, such as the power to create a duplicate of herself or to stop time, thanks to new magical accessories. These new powers come with their own unique rules and limitations, further testing her resourcefulness. By the end of her story, Himeko undergoes significant development, transforming not just physically through magic, but internally from a tomboyish girl into a more refined, mature, and confident young woman who no longer needs magic to define her worth. Though she eventually loses her magical abilities when the trial period ends, she retains the invaluable friendships, memories, and personal growth she gained along the way.