Hatsuri Momoi is a main character in her respective story, identifiable by her pink hair which matches the color theme of her name, as momo translates to pink or peach. She is a first-year student with a birthday on September 20, and her height is 152 centimeters. Her appearance includes pink eyes and a characteristic twin-tail hairstyle, often adorned with ribbons.

Hatsuri comes from a family that operates a construction business, and this family has deep, longstanding ties to the Shirogane family. Prior to becoming involved with the main group, she is already a member of her school's theater club. Her personality presents an interesting contrast; she has a delicate and beautiful outward appearance, but this belies a headstrong and determined nature. She is described as someone who tends to dive headfirst into things without looking, and once she starts on a path, she refuses to stop. This enthusiastic but intense disposition is sometimes expressed as a tendency to go overboard, particularly regarding her specific interests.

Hatsuri is brought into the group when the other heroines realize they need a pink-colored member who possesses knowledge of special effects to help elevate their local hero shows. Her background in the theater club likely contributes to this skillset, and her role becomes that of the pink heroine, which aligns with the team's color-coded motif. A notable part of her development involves learning to channel her headstrong and explosive passion for special effects into her performances, as her natural inclination is to go beyond reasonable limits. Her key relationships are primarily with the other heroines, and her family's connection to the Shirogane family suggests a pre-existing bond with those characters that informs her integration into the team.