Kaede Saito is a prominent supporting character in Angelic Layer, recognized as one of the most skilled and beloved players in the game. She is a sixteen-year-old high school student with a birth date of October 14. Her most defining physical traits are her long, chestnut-brown hair, often styled into two loose braids tied with red ribbons, and her large, round glasses, which give her a studious and gentle appearance. She is frequently seen in her school uniform from Kiyozono Academy, a distinctive ensemble featuring a maroon dress and a white sailor-style collar. Her gentle smile is a hallmark of her personality, earning her the nickname "the smile that illuminates the heart".

Underneath her calm and kind exterior, Kaede possesses a strong and determined spirit. She is consistently polite, well-mannered, and treats others with a warm, almost maternal care. This nurturing instinct is a direct result of her past; having lost her mother at a young age, she channels these feelings into her role as a Deus, the term for an Angelic Layer player. She considers her angel, Blanche, as her own daughter, vowing to continue fighting in tournaments for as long as her angel desires it. Despite her gentle demeanor, she is a fierce competitor who does not shy away from a challenge and has a strong sense of justice, as shown when she disapproves of unsportsmanlike conduct.

Kaede’s primary motivation in Angelic Layer is intertwined with her personal history. The loss of her mother left a void that she partially fills through her relationship with Blanche. Her journey as a Deus began when a friend of her father gave her a penguin plush toy that contained an Angel Egg, sparking her path to becoming an elite player. Throughout the story, she serves as both a rival and a mentor to the protagonist, Misaki Suzuhara. Recognizing Misaki's potential, Kaede quickly befriends her, offering guidance and a positive example of what a powerful and compassionate Deus can be.

Kaede’s most significant relationship within Angelic Layer is with her best friend, Sai Jounouchi. Despite having opposite personalities, the two share a close bond, and Sai frequently acts as her assistant during tournaments. Kaede’s family life is also notable for its connection to another series, Chobits. She is the older sister of a character named Minoru Kokubunji. Her parents are divorced, which explains why she and her brother have different surnames; she lives with her father while Minoru lives with their mother.

In the world of Angelic Layer, Kaede is a top-tier competitor with remarkable abilities as both a Deus and an angel creator. Her angel, Blanche, is characterized by its incredible speed and graceful, feather-light movements. Its appearance is that of a small, blonde-haired doll dressed in a white, nurse-like outfit. Kaede’s true genius, however, is the unique "Hypermode" system she designed for Blanche. This automatic function activates after the angel has sustained a certain amount of damage, causing it to emit a glow while its speed and power double, making it extraordinarily difficult to defeat. This system even allows Kaede to strategically allow her angel to take hits in order to trigger the more powerful mode.

While she does not undergo a dramatic personal transformation in Angelic Layer, her role is to exemplify the highest ideals of the game. She represents the harmonious blend of technical skill, strategic thinking, and genuine heart. Her development is more about reinforcing her established nature as a supportive, strong, and inherently kind person. Within the larger CLAMP universe, her story continues in a tragic fashion. In the series Chobits, which shares a timeline with Angelic Layer, it is revealed that Kaede passes away from an illness at the age of seventeen. Her memory lives on through her brother, who is so affected by her death that he creates a computer, or persocom, named Yuzuki in her image to cope with his loss.