Makoto Kino is the civilian identity of Sailor Jupiter, the fourth Sailor Guardian to join the main group in the Sailor Moon series. She is introduced as a transfer student to Juuban Junior High School, where she initially struggles with a reputation as a delinquent due to her tall stature, physical strength, and blunt, masculine speech patterns. In reality, Makoto is a deeply kind and gentle person with a strong domestic side. She is an excellent cook and baker, often bringing homemade lunches and treats to share with her friends. She is also skilled in gardening, flower arranging, and various household chores. Her height and strength are a source of self-consciousness, stemming from a past rejection by a senior she admired, who told her he did not like large girls.

Makoto's background is marked by personal loss. Her parents died in a plane crash when she was young, leaving her to live alone and become highly self-reliant. This loss also gives her a fear of airplanes. Her core motivations are rooted in a desire for love, belonging, and stability. She dreams of one day getting married and owning a shop that sells both cake and flowers. In the context of the story, she acts as a protector and a stabilizing force within the team. While Sailor Moon is the leader, Makoto often serves as a physical shield and a source of practical support. She is the physically strongest of the Inner Guardians and excels in hand-to-hand combat, frequently engaging enemies directly. Her role is that of the guardian of protection, using her power to shield her allies.

Her key relationships are defined by her nurturing and loyal nature. She forms an immediate and close bond with Usagi Tsukino, who is the first person to look past her intimidating exterior and become her friend. She shares a particularly close friendship with Ami Mizuno, often studying and spending time together. Her relationship with Minako Aino is marked by a shared tendency to be easily smitten, and they often bond over romantic interests. She also feels a kinship with Mamoru Chiba, as they both understand the experience of being orphans. A notable aspect of her personality is her tendency to fall in love quickly with any man who reminds her of her first crush, a pattern that often ends in disappointment but highlights her romantic and hopeful nature. Over the course of the story, Makoto develops from a solitary and somewhat defensive individual into a confident and integral member of the team. She learns to value friendship above all else and becomes more comfortable with her own dual nature, balancing her strength with her femininity. Her growth is also marked by increasing mastery over her powers and a willingness to sacrifice herself for her friends, as seen when she uses a self-destructive attack to defeat enemies in the first season.

As Sailor Jupiter, her notable abilities are tied to the planet Jupiter. She wields powers over thunder, lightning, and storms, often channeling electricity through an antenna in her tiara. She also has powers related to wood and plants, a reference to the Japanese name for Jupiter, Mokusei. Her signature attacks include Supreme Thunder, which summons a bolt of lightning, and Sparkling Wide Pressure, a powerful electrical blast. In the later seasons, she gains the ability to transform into Super Sailor Jupiter and, in the manga, Eternal Sailor Jupiter, which enhance her powers and grant her new attacks like Jupiter Oak Evolution. Her combination of superhuman strength, martial arts skills, and elemental powers makes her one of the most formidable fighters in the group.