Maki Aikawa is the central protagonist of Air Master, a high school girl who stands out significantly due to her height, which is around six feet, and her boyish, athletic appearance. Her past is rooted in gymnastics, a sport in which she was a champion trained by her mother before her mother passed away. Following this loss, Maki redirected her acrobatic talents into the underground world of street fighting, adopting the nickname Air Master because of her aerial combat style. She lives alone due to a conflicted relationship with her estranged father, Shiro Saeki, a former professional fighter who provides for her financially.

Maki’s personality is markedly different inside and outside of a fight. In her daily life, she is reserved, quiet, and often seems disinterested in her surroundings, preferring to follow her group of friends rather than lead them. She is described by her half-sister as somewhat simple-minded, and her lifestyle is abysmal when it comes to academics, as she rarely attends class and frequently sleeps on her desk when she does. Her primary daily routine is wandering the city in search of opponents who can give her the rush and pressure she craves, as fighting is the only thing that makes her feel truly alive. Despite her rough exterior and lack of interest in romance, Maki becomes noticeably flustered and vulnerable when approached with romantic intent, particularly by the persistent Julieta Sakamoto.

Her role in the story is driven by this search for thrilling battles. She is drawn into the Fukamichi Rankings, a fighting league where she climbs the ranks by defeating a series of powerful opponents. Her motivations are not rooted in revenge or honor but purely in the excitement of combat and self-discovery through challenging her own limits. Maki forms several key relationships. She is fiercely protected of her friends, a quartet that includes Mina, who has an unrequited romantic crush on her, and Kaori Sakiyama, a former model who evolves from a jealous rival into an obsessive friend and training partner. She also has a complex relationship with her father, Shiro, and later meets her younger half-sister, Miori, with whom she shares a distant but respectful bond. Her most persistent pursuer is Julieta Sakamoto, whose romantic advances she both fears and is forced to confront.

Throughout the series, Maki develops from a purely instinctual fighter into a more formidable combatant. She possesses the remarkable ability to replicate almost any move she sees or is hit with, integrating these techniques into her own arsenal. Her fighting style is a fusion of gymnastics and martial arts, allowing her to use walls and objects as springboards for devastating kicks and throws while seemingly flying through the air. Her signature moves include the Air Spin Driver and the Air Cutter, and she eventually learns to master the flow of air, enabling her to dodge attacks with her eyes closed. Her notable abilities include her resilience, immense physical strength, and a genius-level instinct for combat that allows her to dominate in one-on-one fights as well as against entire groups of enemies. Later in the narrative, Maki begins working as a policewoman, adopting the alias Tiger Master after single-handedly raiding yakuza gangs. She also founds a dojo called the Tiger Cubs Den, where she trains children in martial arts.