Miyuki is a Japanese high school student and central character in all official media. She has distinctive blonde hair and blue eyes, visually referencing Lewis Carroll's Alice. Her consistent Japanese school uniform facilitates action sequences during adventures.

Miyuki repeatedly experiences involuntary transportations across seven surreal dimensions: Wonderland, Looking Glass Land, TV Land, Part-Time Job Land, Mah-Jongg Land, Video Game Land, and X-Land. Each journey begins with mundane activities interrupted by a portal mechanism—like a rabbit hole, mirror, or television screen—that displaces her. These worlds are exclusively populated by women who express attraction through advances, suggestive game invitations, or attempted physical contact.

Miyuki reacts with consistent distress, verbal protests, and attempts to flee. Her shy, flustered demeanor contrasts sharply with the inhabitants' provocative behavior. Each adventure concludes with her awakening or returning to her original reality, though dream-world elements like recurring characters or objects manifest in her waking life, implying cyclical unresolved experiences. This pattern repeats identically across all chapters and adaptations.

No substantive character evolution occurs. Her background remains undefined beyond student status, lacking exploration of family, personal history, or internal motivations beyond reacting to immediate circumstances. She remains consistently reactive, never developing strategies to avoid or understand displacements.

Miyuki appears in non-speaking cameo roles in other CLAMP works including "CLAMP in Wonderland," "CLAMP School Detectives," and "Tsubasa: Reservoir Chronicle." These appearances maintain her established design without contributing to backstory or narrative expansion.