Mami Sakura is a junior high school student who unexpectedly acquires psychic abilities including telekinesis, telepathy, and teleportation. She primarily uses these powers to assist people in distress, driven by an innate ability to sense when individuals require help. Her teleportation initially functions unpredictably, causing collisions, until Kazuo Takahata designs the "Teleportation Gun" heart-shaped brooch to grant controlled teleportation via launched marbles. Her cellular-level telekinesis enables manipulations like extracting cancerous cells, while her telepathy accesses others' thoughts and dreams.

Mami lives in a suburban area with her parents. Her father, Juro Sakura, is a painter who frequently asks her to pose nude for his artwork. Her mother, Naoko Sakura, works at a newspaper's foreign desk and often criticizes Mami's academic performance and domestic skills, particularly her cooking. Mami has a French ancestor, which Kazuo believes is the source of her powers; due to historical associations with witch hunts, she conceals her abilities from her family. Characterized as bright yet careless with a tendency to meddle, she struggles academically and with household chores, causing tension with her mother. She owns a pet dog, Konpoco, resembling a raccoon dog or fox, which understands human speech and reacts strongly to being misidentified.

In the film *Hoshizora no Dancing Doll*, Mami aids a puppeteer troupe facing disbandment after developers threaten their performance space. When a member withdraws before a key preschool performance of *Little Red Riding Hood*, she steps in to ensure the show proceeds. Concurrently, she encounters a girl distraught after her father, a television executive, discards a doll cherished as a memento of her deceased mother. After failing to retrieve the doll from a landfill, Mami collaborates with the puppeteers to stage an impromptu outdoor show near the girl's residence, aiming to shift her emotional attachment toward her father. Later, when the troupe's leader, Hideki, considers quitting, Mami uses her powers to animate puppets in a park, voicing them to express their "desire" to continue storytelling. This display of puppets moving independently through the air, combined with encouragement from troupe member Tomoko, persuades Hideki to persist.

Mami's personality combines impulsiveness with deep empathy. She frequently acts without fully considering consequences, motivated by a desire to alleviate others' suffering, though her powers sometimes cause unintended disruptions like teleportation mishaps. Despite her naiveté, she demonstrates resourcefulness, such as manipulating puppets to reignite Hideki's passion or orchestrating therapeutic performances.