Primula is one of the main characters of the Shuffle! series, including Shuffle! Memories. She is an artificial life form known as a homunculus, created through a joint scientific project between the worlds of the Gods and the Devils. The purpose of this project was to study magic and improve how it could be used by creating beings who carried more magical energy than gods or demons could naturally possess. Primula is the third of these creations, and as a result she holds more magical power than almost anyone she meets, though she is initially unable to control that power. She appears as a petite sixteen-year-old girl with long silver-gray hair, violet eyes, and pointed ears, and she is almost always seen carrying a small stuffed cat that serves as her comfort item.

Primula was raised in isolation in a laboratory setting, and before coming to the human world her only deep bond was with Lycoris, another experimental subject whom she regarded as an older sister. Before Lycoris died, she gave Primula a stuffed cat that had originally been a gift from Rin, and Primula treasures it as a memento of that relationship. Because of her lonely upbringing, Primula is quiet, stoic, calm, and emotionally reserved, and she struggles to express her feelings or interact naturally with others. After hearing stories about Rin, she grows curious about him and travels to the human world to meet him. Her deeper motivation is tied to her desire to understand emotions and become more stable, since both her heart and her power remained out of control while she was unable to express herself.

In the story, Primula is taken into the household of Rin and Kaede, where she experiences ordinary human life for the first time. Rin becomes her closest friend and love interest, and through his patience and kindness she begins to open up emotionally. He also helps her learn to control her immense magical abilities during a critical moment in her development, which marks a turning point for her. Kaede acts as a guardian and caretaker, providing her with clothing and daily care, and Primula grows attached to her in return. Over the course of the series, Primula shifts from a withdrawn and seemingly emotionless girl into someone who is more talkative, cheerful, curious, and affectionate, while still keeping her gentle and somewhat odd manner. By the later part of the anime adaptation she begins attending high school like the other characters.

In terms of abilities, Primula is regarded as the most powerful magician in the series. She is skilled in many forms of magic, including restoration, precognition, teleportation, mind alteration, elemental magic, and the manipulation of time and space. In the anime her prophetic ability appears in subtle ways, such as warning Rin and Kaede about an earthquake just before it happens and preparing medicine for an illness before any symptoms appear. Her main weakness is her inability to control her own vast power, which is closely connected to her emotional state. Her journey in the human world, her relationships with Rin and Kaede, and her growing ability to express herself all play a central part in her development into a more emotionally open and stable person.