Lucy Maria Misora, alias Ruuko Kireinasora, is an enigmatic exchange student who claims extraterrestrial origins from the third planet “ruu” in the constellation Ursa Major 47. She enters Takaaki Kouno’s class following a peculiar encounter, her presence marked by waist-length lavender hair, crimson eyes with a faint purple tint, and a slender, pale frame. Her attire consists of a pink sailor-style school uniform paired with a red miniskirt, white accents, black socks, and brown shoes.

Eccentric and cryptic, she communicates in a unique “ruu” language—a starfish dialect initially unintelligible until she taps her head to adjust her translation device. Known for raising her arms while uttering “rū” and referring to humans as “ū,” she exhibits a whimsical, elusive demeanor and demonstrates an ability to commune with animals.

In a fantasy RPG spin-off, she is transported to a fictional world alongside others, assuming the role of a magic user within the party. Collaborating to defeat a final boss and return to their original world, her narrative across media iterations consistently highlights her alien identity and peculiar traits, centering on her established role in group dynamics without expanding on individual evolution.