Kaere Kimura is a female student with long blonde hair, noted for wearing a distinctive suit, tie, and short skirt uniform that sets her apart from classmates. She is left-handed. Her background involves returning to Japan after living abroad, exhibiting American cultural traits and language despite reports suggesting only three months outside Japan; her exact country of origin remains unspecified. This cross-cultural exposure triggered dissociative identity disorder stemming from conflicting cultural identities.

She developed two primary alters: Kaede embodies a gentle, traditional Japanese woman proficient in local customs, while Kaere exhibits aggressive foreign mannerisms, vocally criticizing Japanese culture and frequently threatening litigation over minor annoyances. The name "Kaere," derived from the imperative form of "kaeru" (to return), functions as a linguistic trigger potentially activating personality switches, with Kaere's personality dominating more often. Her full name may reference Japanese singer Kaela Kimura.

A third personality, previously existing as a balance between Kaede and Kaere, fractured due to a psychotic breakdown triggered by classroom interactions after her transfer. Later developments reveal additional split personalities representing other countries, expanding beyond the initial dichotomy. Her behavioral patterns include initiating lawsuits for perceived offenses, such as accusing her teacher of sexual harassment after he viewed her underwear during a suicide intervention. She frequently exposes underwear with unusual designs, contributing to recurring fan service sequences.

She reportedly tutors geometry part-time. Her birthday is February 5. Cultural contradictions define her narrative role, juxtaposing critiques of Japanese society with exaggerated foreign customs while navigating identity instability.