Luna is a central character in the anime Yu-Gi-Oh! 5D's. She is the fraternal twin sister of Leo, and she is one of the five Signers chosen by the Crimson Dragon, bearing the Mark of the Dragon's front claw. Born with a naturally frail constitution, Luna is shy, gentle, and introspective. She enjoys reading and spends much of her time in quiet reflection. Unlike many other duelists, Luna has a unique connection to the world of Duel Monsters spirits, having gained the ability to see and communicate with them after spending a significant amount of time in the Duel Monsters Spirit World during a coma. Among the spirits she befriends are Regulus, Kuribon, and her most trusted partner, Ancient Fairy Dragon, which is also her Signer Dragon. Her bond with these spirits shapes her personality, making her compassionate and protective toward them.

Luna's motivations stem from a desire to protect her loved ones and maintain the peace between the human world and the spirit world. She deeply admires and supports Yusei Fudo, often providing calm wisdom and emotional strength to the group. Despite her young age, she is recognized as one of the strongest Signers, though her physical stamina is limited—she tends to become tired after a duel. Her role in the story is pivotal: she participates in the Fortune Cup tournament, battles alongside the other Signers against the Dark Signers, and later helps confront the threats posed by the organization Iliaster. Her key relationships include her twin brother Leo, who is energetic and often impulsive, providing a balance to her reserved nature; she also forms close bonds with fellow Signers Yusei, Jack Atlas, Akiza Izinski, and Crow Hogan. Over the course of the series, Luna grows from a shy and physically fragile child into a more confident duelist who can stand on her own, using her empathy and understanding of duel spirits to overcome challenges.

In terms of abilities, Luna is a skilled duelist who plays an Ancient Fairy Deck, primarily using Fairy, Plant, and Beast-Type monsters. Her deck often revolves around field spells and summoning her ace monster, Ancient Fairy Dragon, which can restore life points, protect her field, and facilitate Synchro Summons. She also possesses the innate talent to sense and converse with Duel Monsters spirits, which gives her unique insights during duels and allows her to forge strong partnerships with her cards. Her Signer mark grants her a connection to the Crimson Dragon, enabling her to participate in the ancient destiny that binds the Signers together. Luna’s quiet determination and deep bond with her monsters make her an indispensable member of Team 5D's.