Kaede Sendōin is a student in the second year of middle school at the prestigious Kamihoshi Girls' Academy. She is a member of the星守者 (Star Guardians), a group of girls chosen to protect the world. Her family, the Sendōin household, is of significant importance as one of the three families that support the Star Guardians, and Kaede is the only member of her lineage to have become a Star Guardian herself. Her background is one of immense wealth and privilege, with her family owning private villas across the globe and their own land, sea, and air exploration teams.

Kaede’s personality is defined by an intriguing contradiction between her noble upbringing and her genuine interests. She has a high degree of pride and can be willful, often speaking with the elegant and formal tone expected of a young lady from a powerful family. However, beneath this aristocratic exterior lies a deep and enthusiastic love for the culture of common people. She is fascinated by things like vending machines and instant ramen, even considering the ability to prepare instant food with hot water to be a form of magic. While her father is described as very strict, Kaede herself is not haughty in a malicious way; she is a hardworking girl who tries her best, even if her unique personality sometimes gets lost among her more eccentric peers. She also has a hidden passion for art, particularly the works of Monet and Impressionism, and enjoys studying painting. Another notable personal quirk is her love for singing Tosca opera, a talent that is unfortunately described as being quite terrible.

Kaede’s primary motivation as a Star Guardian is to protect the world from the mysterious creatures known as Iros. Early in her personal story, she held a strong prejudice against a feral girl named Sadone, believing her to be an Iros and strongly opposing any efforts to rescue her. This initial stance changes dramatically over time. As the situation unfolds and she spends more time with Sadone, Kaede develops a deep affection for the girl. Seeing that Sadone has no one else to rely on, Kaede makes the decision to take her in and care for her. This marks a major turning point, as her motivations shift from merely following orders to a deeply personal commitment to protect and provide a family for someone in need.

Within the larger story, Kaede serves as a key figure in the星守班 (Star Guard Class). Her wealthy family often uses its resources to host grand parties and events for the entire class. In alternate storylines, she is also shown to be a member of the idol group "Tiara" and the music band "Clover."

Her relationships are quite significant. Initially, she is shown to have a close friendship with Michelle Watagi. However, her most transformative relationship is with Sadone. After taking her in, Kaede and Sadone become inseparable, living together and developing a bond described as being like that of real sisters. This new familial bond becomes the central relationship in her life, overshadowing her earlier friendship with Michelle. She also has a noted fondness for the player character, who serves as the class teacher.

Kaede’s personal development is most clearly seen in her journey from rejecting someone considered an outsider to becoming that person’s most devoted protector and family member. This decision to care for Sadone highlights her growth from a somewhat self-centered aristocratic girl into a more compassionate and responsible individual.

In terms of abilities, Kaede uses a weapon called the Kikuchi Spear. Her星衣芙萝菈 (Flora Star Uniform) is primarily purple in color, and her representative flower is the rose. In some contexts, she is also known to use a star dress named Phoenix. Her hobbies include horseback riding in her spare time, and she relieves stress by taking walks around town.