Chibiusa, often referred to as the "Small Lady," appears in the 1993 film Sailor Moon R: The Movie as a young girl from the future who has come to live in the present day. Her presence in the story is well-established, as she is familiar with the true identities of all the Sailor Guardians and resides alongside Usagi Tsukino and the other characters in contemporary Tokyo. Throughout the movie, her demeanor is consistently energetic and outspoken, often serving as a grounded counterpart to the more dramatic and childish Usagi. For instance, when Usagi proudly and incorrectly claims to be the strongest, most elegant, and the leader of the Sailor Guardians, Chibiusa is shown shaking her head at what she perceives as Usagi's delusions of grandeur. Despite their constant bickering, which forms a core part of their relationship, Chibiusa cares a great deal for Usagi, and her loyalty to the Sailor Guardians is unwavering.

In the context of the movie's narrative, Chibiusa's primary role is that of an observer and supporter. Her motivation is not to drive the main conflict, but to stay close to Usagi and her friends while they face the alien Fiore and the malevolent Xenian Flower. She is present during the initial meeting with Fiore at the Jindai Botanical Gardens and witnesses the ensuing struggle as Fiore attempts to drain humanity's life energy. While she does not participate directly in the major battles, she acts as a reassuring presence. For example, when Usagi becomes discouraged and fears that her friends will be hurt while trying to rescue Mamoru, it is Chibiusa who urges her not to give up, providing encouragement that helps steel Sailor Moon's resolve to confront Fiore. Her intimate understanding of the group's dynamic allows her to react with exasperation at their teasing or worry, but her faith in their victory remains absolute.

Her most significant relationships in the film are with her future parents, Usagi and Mamoru. Her connection to them is a given fact, and she is frequently seen reacting to the ups and downs of their romantic relationship. The film presents Chibiusa as a character who, despite her small stature and young age, has a developed personality and a secure place within the central group. She does not undergo a major personal development arc or transformation within the events of this specific movie, as her character had already been introduced and established in the television series. Instead, her role is to be a steadfast, if occasionally critical, friend and family member. Her notable abilities are not the focus of this film's action, as she does not transform into her Sailor Chibi Moon form or use any major attacks on screen. Rather, her value comes from her perceptiveness, her courage, and her ability to voice her faith in the Sailor Guardians when they need it most. By the movie's conclusion, her optimism is validated when the Senshi successfully divert the asteroid and Sailor Moon is revived, proving her assurance to the cats Luna and Artemis that "the girls are all right" to be correct.