Hiromi Nozawa is a sixth-grade elementary school student. Outwardly mature and resilient, she projects stability while feeling internally as though she is "falling apart." This conflict stems from her family situation. Her parents are consistently absent; her mother manages a busy hotel and her father travels overseas for work. Consequently, Hiromi spends most of her time under the care of her live-in nanny, Fumie Morita, and her tutor, Keisuke Kimura.

This stability deteriorates when Hiromi learns her parents are considering divorce, forcing her to confront the possibility of choosing which parent to live with. Compounding her distress, Hiromi harbors a romantic attachment to Keisuke. His impending marriage intensifies her fear of abandonment and amplifies her sense of isolation.

Her primary emotional support is her pet dog, Junkers, a miniature schnauzer who possesses the ability to speak human language and grant three wishes. Hiromi confides her deepest fears, loneliness, and familial struggles exclusively to Junkers, sharing feelings she expresses to no one else, making him her most trusted companion.

Faced with her parents' potential separation, Hiromi struggles to communicate her needs to them. She often endures her suffering silently, masking her true emotions behind a facade of happiness and self-reliance to appear mature and avoid burdening her parents. This tendency to internalize her pain is defining.

Her reliance on Junkers leads her to utilize his wish-granting ability to mend her fractured world. However, the consequences of these wishes, particularly their impact on Junkers himself, contribute to her emotional journey. Navigating her parents' crisis, coping with her unrequited feelings, and confronting the limitations of magical solutions force Hiromi towards personal growth. She gradually learns to process complex emotions and adapt to challenging familial changes.