Hisako has short pink hair with bangs that reach her chin. In junior high, her hairstyle had a rounder shape, and in the early parts of the series, her fringe reached her eyebrows before later parting to the left. By her second year, she wears her hair in a slightly shorter bob.

She usually wears the standard Tōtsuki seasonal uniforms, even outside of class, and dons a plain white chef’s uniform when cooking. When working behind a computer, Hisako is sometimes seen wearing glasses. Her measurements are 80 cm bust, 56 cm waist, and 79 cm hips (31-22-31).

Hisako is a loyal and devoted friend to Erina Nakiri, rarely seen apart from her. As Erina’s secretary, she meticulously manages her schedules and assignments, demonstrating impressive organizational skills for her age. Deeply dedicated to Erina’s success, Hisako views her as an “Empress” and prioritizes Erina’s achievements over her own. This devotion stems from their childhood, as Hisako has always been content to follow behind Erina. She also helps Erina navigate modern interests, such as introducing her to shōjo manga. Like Erina, Hisako can be prideful and tends to look down on others, often defending Erina’s honor in her stead.

Her pride was shaken after losing her Quarterfinal match in the 43rd Annual Tōtsuki Autumn Election to Akira Hayama, causing her to question her worth as Erina’s secretary and friend. However, with encouragement from Sōma Yukihira, Hisako regained her confidence and resolved to stand beside Erina rather than behind her. Since then, she has become more open-minded and friendly, even forming an unexpected friendship with Sōma.

• The nameHisakomeans “Eternal Child”, “Child of an Old Story” (when written with a different kanji), “Everlasting Child” or “Auspicious Child”.
  • Hisako(緋沙子) uses the kanji for “scarlet” (緋) (hi), “sand” (沙) (sa) and “child” (子) (ko).
    • The nameHisakois a pun of the Japanese wordhisho(秘書), which means “secretary”. This has been noted byAlice Nakiriand confirmed by the authorYūto Tsukuda.^[13]Alice further teases Hisako by combining her name intoHishoko(秘書子) which later becomes her nickname by many of her classmates.
• Hisako’s surnameAratomeans “fresh, new” (新) (ara) and “door” (戸) (to).