Luna is a prideful young girl who has always taken great pride in being the ace of her high school, excelling in both academics and physical education. She was confident in her position as the school’s top student…until Arie transferred in and took her place as the ace of the physical division.

Disgruntled by the sudden challenge to her status, Luna declared Arie her rival and frequently challenged her to various physical competitions. Despite Luna’s determination, Arie consistently came out on top. What began as a fierce rivalry gradually developed into a close friendship as the two spent more time together.

After graduating high school, both Luna and Arie applied to Star Center. Luna was accepted as an officer, while Arie was assigned to the less prestigious position of space janitor. Luna occasionally teases Arie about her job, much to Arie’s annoyance.

Despite her prideful and competitive nature, Luna has developed a secret crush on Arie. She stubbornly denies her feelings whenever the subject comes up, refusing to admit that her former rival may have become something more.