Haruka is depicted as both intelligent and attractive. As a child, she was once trapped in the basement of the Transportation Museum, where she was rescued by Naoto Takayama. This childhood experience not only established her connection with Naoto but also influences her later feelings of jealousy when she sees him grow close to other girls, with the exception of Aoi Sakurai.

Haruka comes from a distinguished family background; her grandfather previously served as the president of Japanese National Railways (JNR), and his connections within the railway world, such as with Katamachi, the stationmaster of Tokyo Station, provide her with strong ties to the industry. While her father initially disapproved of JNR, he eventually accepted her decision to participate in the student on-the-job training program.

During her time studying in England, Haruka became acquainted with Prince Bernina of Atera, which later proves significant when she acts as his interpreter during his visit to Japan.

Haruka is depicted with auburn-pink hair that flows down her back and dark brown eyes. She is noted within the series for her attractive figure, which often draws attention from those around her.

While on duty as a member of the Fourth Peacekeeper Squad, she wears the official security uniform, consisting of a white blouse, tie, skirt, white gloves, flesh-colored pantyhose, and black leather shoes.

Haruka is portrayed as a shy and soft-spoken individual, often displaying nervousness in unfamiliar or high-pressure situations. Despite her timid nature, she is highly intelligent and excels academically, with an exceptional memory that allows her to recall train timetables at Tokyo Station with remarkable accuracy, including both passenger and freight schedules.

Her lack of confidence sometimes affects her performance in practical training. During firearms practice, her slow reflexes caused her to accidentally fire into the ceiling, leaving her shaken and on the verge of tears. Nevertheless, her strong work ethic and supportive demeanor make her a dependable member of the Fourth Peacekeeper Squad, complementing the more assertive personalities of her teammates.

Naoto Takayama
Haruka first becomes acquainted with Naoto during their initial railway training classes, where he quickly becomes her first close friend. Although their interactions often involve embarrassing moments, such as when Naoto accidentally sees her underwear Haruka consistently treats him with kindness and warmth. Subtle romantic undertones appear throughout the series, though their relationship remains complicated by the presence of Aoi Sakurai, creating a love triangle in which none of the parties openly acknowledge their feelings.

Aoi Sakurai
Haruka meets Aoi during the opening ceremony of the Railway Academy, and the two quickly become friends. As fellow members of the Fourth Peacekeeper Squad, they share a strong sense of camaraderie and mutual trust. However, Haruka also views Aoi as a romantic rival due to their shared interest in Naoto, adding tension beneath their otherwise cooperative relationship.

Haruka’s given name is written in hiragana (はるか), which does not carry an inherent meaning in this form. When rendered in kanji, however, it can take on several interpretations. Possible variations include 遥, meaning “distant” or “remote”; 春花, combining “spring” (春) with “flower” or “blossom” (花); and 晴香, which can be read as “clear weather” (晴) paired with “fragrance” (香). Her surname, Kōmi (小海), is written with the kanji 小 (ko), meaning “small,” and 海 (umi), meaning “sea” or “ocean.” Together, her full name can be interpreted as “Haruka of the small sea,” which reflects natural and delicate imagery consistent with her gentle personality.