Born May 19th, Maruzensky was raised by a ballet dancer father and a mother who instilled a love for past cultural trends, resulting in her use of outdated slang and a preference for retro styles. She commutes to Tracen Academy in a meticulously maintained second-hand red supercar, nicknamed "Tacchan" and inherited from her father. She drives this car, likely modeled after a Lamborghini Countach LP400, with notable speed and drifting skill, though she struggles with cautious driving. She is one of the few academy students living independently, not in the dormitories. Her personality combines cheerfulness and serenity, making her a respected "big sister" figure and role model. While projecting confidence and positivity, she privately grapples with feelings of inadequacy due to lacking a specific dream or ambition, unlike peers with clearer goals. This internal conflict initially led her to reject trainers after early success. She eventually embraced finding joy in running itself, recognizing her value as an inspiration without needing grand aspirations. She mentors juniors like Special Week, who finds her warm and reassuring, and supports characters such as Mejiro Ardan through activities like collaborative writing performances. Maruzensky excels at front-running tactics, using her speed to dominate races from the start, though she adapts when needed. Beyond racing, she maintains strong academics and a distinctive style, favoring routines like morning shampoo hair care and post-drive coffee milk. She dislikes being a passenger due to carsickness and finds modern technology, especially smartphones, challenging. Expanded lore depicts her as a bloodline ancestor to several other horse girls, including Sakura Chiyono O, a descendant who fulfilled Maruzensky's unrealized dream of competing in the Japanese Derby. Alternate narratives explore her passing unfulfilled ambitions to this "daughter" figure. Her influence surfaces across storylines as guidance, comic relief via retro quirks, and motivation, notably within Team Rigil where she mentors speed-focused characters like Grass Wonder. Her character arc mirrors her real-life counterpart's history; restrictions on foreign-bred horses prevented participation in major races like the Japanese Derby. The historical Maruzensky died in 1997, with tributes from his owner, who mourned him like a son, and a ceremonial gold medal placed in his coffin, informing the character's legacy themes.