Ayumi Hagiwara is a young girl separated from her mother. Found lost by Minori Sumitomo, Ayumi views Minori's unconventional approach to comfort her with suspicion. Takaya Murase intervenes and successfully calms her. This encounter sparks an immediate romantic interest in Takaya within Ayumi, leading her to actively seek opportunities to be near him.

Her mother, Kanae Hagiwara, is an attractive woman with a notably curvaceous figure. Kanae also expresses romantic interest in Takaya, resulting in a familial rivalry as both mother and daughter compete for his attention.

Ayumi possesses ochre hair styled in odango, reaching her ears, and red eyes. She consistently presents a childlike appearance. A stuffed rabbit wearing a tuxedo is her constant companion.