Utano Sasō attends Seio Girl's Academy as a junior to protagonist Chihaya Kisakinomiya. She presides over the flower arrangement club and regularly visits the gardening club, fueled by her personal horticultural interests. Her parents impose strict disciplinary standards, which she outwardly follows without question, yet internally she craves more personal freedom.

Peers address her as "Gozen" (Her Highness), a title acknowledging her perceived elegance and dignified demeanor. This reputation makes her a frequent advisor to other students and positions her as a prime candidate for the prestigious Elder sister role, a student representative position. Her bond with Chihaya forms because he treats her without special deference, unlike peers influenced by her status.

Her story unfolds solely within the PC version of the visual novel *Otome wa Boku ni Koishiteru: Futari no Elder*, exploring her interactions and potential relationship with Chihaya. She does not appear in the anime OVA adaptation or other media beyond the original game.