Haruka Momochi is a student at Akane Academy and a supporting character in World Break: Aria of Curse for a Holy Swordsman. She is a second-year student and a member of the combat unit known as the Strikers, where she holds the rank of C-class at the beginning of the story before eventually advancing to B-class and later A-class. She is often referred to by the nickname Momo-senpai by the protagonist, Moroha Haimura.

Physically, Haruka is a petite young woman of average height with a small and slim build that makes her appear younger than her actual age of sixteen. She has cheek-length chestnut brown hair and brown eyes, and is typically seen wearing her school uniform with black knee socks, though she also wears the Striker Unit combat uniform during missions. Her appearance is boyish and lively, with an unpretentious atmosphere, and she is known to be self-conscious about her feminine appeal, particularly when compared to other female characters such as Shizuno Urushibara or Satsuki Ranjou. This insecurity stems from past comments from others that made her feel more like a boy than a woman, and she sometimes downplays her own abilities as a result, finding them useless compared to other combatants.

In terms of personality, Haruka is tomboyish, confident in her combat skills, and possesses a competitive streak. She frequently challenges Moroha and Satsuki to training and sparring sessions, and her confidence is rooted in her genuine abilities as a Savior. Hinata has strong emotional responses and can have difficulty controlling her emotions properly. It has been hinted on multiple occasions that Haruka has developed a crush on Moroha as a result of his assistance to her in various situations, though she struggles to express these feelings as openly as others and often makes comments about his girlfriends instead. She is also known to disagree with Moroha's responses when he comments on her appeal, reflecting her deeper insecurities about her femininity.

Haruka's role within the story is as a regular member of the Strikers and one of Moroha Haimura's primary partners in combat. Her most notable ability is her incredible speed, which is considered the fastest among all the students at Akane Academy. Only Moroha Haimura is said to be capable of matching her speed, making her a valuable asset on the battlefield where she undertakes the role of examining the heretical Metaphysical enemies and running through the battlefield at superhuman speed alongside Moroha. As a speed-type fighter, her combat strategy involves seizing opportunities to turn the fight around with a single decisive strike, though this approach is less effective against opponents who leave no openings.

Her abilities extend beyond mere speed, as she demonstrates the capacity to create up to five alter egos or clones of herself using a technique called Tamrang, which is noted as a super-high derivation of Shinjoktong. This is particularly impressive given that Moroha himself can only divide into four clones, highlighting Haruka's significant skill and hard work. Her dedication to training and her natural talents have earned her recognition, and Jin Isurugi has recommended her for promotion to higher ranks based on her abilities, which stand alongside those of Satsuki Ranjou.

Throughout the course of the narrative, Haruka develops from a confident but internally insecure young woman into someone who gains greater confidence in herself, particularly after receiving advice from Moroha that helps her accept her body and abilities. Her relationship with Moroha deepens as they work together as partners, and she becomes an increasingly important figure in his life. In a significant development at the end of the light novel series, Haruka is revealed to be the first among the heroines to conceive Moroha's child, marking a substantial evolution in her role from a supporting character with a hidden crush to a central figure in the protagonist's personal future.