Lita Kino, known in her transformed state as Sailor Jupiter, is one of the central characters in Sailor Moon R: The Movie. She is a fourteen-year-old student at Juuban Junior High School, notably taller and physically stronger than most girls her age. Her background is marked by personal tragedy: she lost both parents in a plane crash when she was young and has since lived alone in an apartment, developing a strong sense of self-reliance. This independence, combined with her athletic build and a tendency to use masculine speech patterns, initially leads others to spread rumors that she is a delinquent who was expelled from her previous school for fighting. In reality, Lita possesses a gentle, nurturing, and deeply romantic nature. She is skilled in all domestic arts, particularly cooking and baking, and her greatest dream is to get married and one day open a combined flower and cake shop. She also loves gardening, flower arranging, and collecting cute, feminine accessories, creating a duality that defines her character.

Her motivations are rooted in protecting those she cares about. As Sailor Jupiter, she fights to defend her friends and the world from evil, driven by a strong sense of loyalty and justice. Her role in Sailor Moon R: The Movie is as a key member of the Sailor Guardians, using her formidable physical strength and electrical powers in battle. She is the fourth guardian to join the team, introduced after she defends Usagi Tsukino from a group of bullies. In the movie, she stands alongside Sailor Moon, Sailor Mercury, Sailor Mars, and Sailor Venus to confront the film's antagonist, contributing both her combat prowess and her emotional support to the group.

Key relationships define her journey. She forms a close bond with Usagi, who becomes her best friend and the leader she respects deeply. She also shares a warm friendship with the other inner guardians, often acting as a big sister figure. Lita is notably susceptible to romantic infatuation; she frequently falls for men who remind her of an unnamed older boy who rejected her before the series began, a pattern that persists in the movie era. This tendency adds a layer of vulnerability to her otherwise confident demeanor.

Throughout the events of Sailor Moon R, including the movie, Lita undergoes subtle character development. She learns to trust her friends and rely on them, overcoming the loneliness that marked her early life. Her fighting abilities also advance, allowing her to use increasingly powerful electrical attacks.

As Sailor Jupiter, her notable abilities include superhuman strength that allows her to lift and throw opponents with ease, as well as mastery of martial arts. She wields powers over lightning and storms, most famously the Supreme Thunder attack, in which she channels a bolt of lightning through a small antenna on her tiara and hurls it at her enemies. She can also manipulate plants to a limited degree, summoning gusts of flower petals to obscure an enemy's vision. Her courage and unwavering determination make her one of the most reliable fighters in the team, and she often uses her strength to shield her companions from harm.