Kaede is a kind and thoughtful high school student who forms a significant connection with Ren, the protagonist, during his return to the human world in the latter half of the story. She has a calm and encouraging personality, often demonstrating a level of maturity and perceptiveness that allows her to understand Ren's inner struggles. Physically, she is a beautiful girl with short black hair and light skin, and she is frequently seen with a book, indicating a love for reading.

Her background is that of an ordinary student living in Shibuya, and her primary motivation is driven by empathy and a genuine desire to help Ren navigate the human society from which he has been separated for many years. She sees that Ren is struggling with his identity and offers him a different perspective on strength, one that values knowledge, education, and human connection. She admits that her own efforts to get good grades are motivated by a wish to make her parents happy, a confession that helps her relate to Ren's feelings of obligation and loneliness.

In the narrative, Kaede acts as a guide to the human world for Ren, helping him to read and preparing him for a life he had long abandoned. Her role becomes crucial when Ren faces an intense emotional crisis, specifically when he is in danger of succumbing to the darkness within his own heart. In a pivotal moment, Kaede offers him comfort and gives him a bracelet she used to wear, telling him that he is not alone and that others share his feelings of rage and resentment. This speech and the symbolic bracelet directly help snap Ren out of his anger during the film's climax.

The key relationship for Kaede is with Ren. While the film never explicitly confirms a romantic relationship, they form a very strong bond characterized by mutual support and trust. Despite being suddenly made aware of the existence of the beast world during a crisis, Kaede takes the information in stride and helps Ren strategize, proving to be a reliable and unflappable ally. Her presence complicates Ren's life, forcing him to confront the choice between his human origins and his life as a beast warrior.

Throughout the story, Kaede's character development involves stepping out of her own shell to help someone in need, finding courage she might not have known she had. She starts as a quiet, helpful figure and grows into someone who can provide decisive emotional and strategic support in the face of supernatural danger. Regarding notable abilities, she possesses no combat or supernatural skills. Her strengths are entirely emotional and intellectual, including her empathy, her ability to remain calm under extreme pressure, and her intelligence as a student.