Main Moroboshi is a supporting character in the anime Princession Orchestra. She is a classmate of the main character Nagase Ichijo and is known for her lively and energetic personality. In many ways, she shares a similar disposition to Nagase, being described as silly, spirited, and almost like a sister to her. Their friendship forms a key part of her role, as she is primarily seen in relation to Nagase.

Main is a twelve-year-old girl with long green hair that she typically ties into a ponytail. She comes from a family of firework craftsmen, and she is currently in training to follow in that tradition. Her passion for fireworks is a central part of her character, extending to her hobbies and abilities. She loves making fireworks and her special skill is writing the word "fireworks". Other notable traits include her fondness for popping candy, her status as a member of the After-School Club, and that her favorite subject is science.

As a supporting character, Main's presence in the story is limited. Her debut occurs in the episode titled "What Am I Doing," and she appears in a later episode, "This Is Where It Begins". In one episode, she has a non-speaking appearance. Her background as an apprentice firework maker and her close friendship with Nagase define her motivation, though her personal journey is not a primary focus of the overarching narrative.