MIX is an Element candidate and the student council president of the Saint Angel Academy within the Neo-DEAVA organization, appearing in the narrative of the Aquarion series set twelve thousand years after the original Genesis of Aquarion events. She is a young woman with long orange hair, blue eyes, and a notable physical presence, often described by her peers as having an exceptionally developed figure. Her character is defined by an extreme and almost pathological aversion to men, whom she treats as if they are contaminants, a stance she maintains even as the academy transitions to a coeducational environment. This deep-seated misandry stems from a childhood trauma: her father, a travel writer, abandoned the family after falling in love with a woman he met during an assignment at a small, hole-in-the-wall bathhouse. This betrayal instilled in her not only a disgust for men but also an obsessive compulsion to fill any hole or gap she encounters, a habit that manifests in her daily life as well as in combat.

Her Element ability is called Interspace Augmentation, which allows her to fill any void, gap, or aperture at a molecular level. This power is practically the inverse of her eventual romantic partner Andy W. Hole's ability to dig holes. In battle, she uses this power to seal damage on her own mecha, obstruct enemy sensors and exhaust vents, and even neutralize attacks by filling the space they travel through. Her rigid and closed-off personality initially hinders her performance as a pilot, as the Aquarion's power is amplified by emotional openness and connection. Her first genuine union with a male partner begins to soften her stance, and she subsequently develops a turbulent but deeply affectionate rivalry with Andy, marked by frequent arguments but underpinned by genuine care. When the Altean leader demands the surrender of a female student, MIX attempts to sacrifice herself to protect a friend and is instead captured and taken to the alternate world of Altair. There, she becomes a victim of the Curse of Eve, which temporarily transforms her into a male soldier named Mixy, with altered memories. She is eventually rescued and restored to her original form. By the conclusion of the story's conflicts, MIX has been returned to her female body and, along with her peers, embraces a new era in which romantic relationships are no longer forbidden, having overcome her personal trauma and developed a more open and trusting nature.