Doll Izumi stands ready as one of the three primary Doll Knights guarding Licca Kayama, princess of the Doll Kingdom. She materializes as a protective guardian summoned directly into perilous situations through the power of the magical Calling Choker. Activating this summoning requires the precise incantation: "Fururu Furora Gurine Guraine."

Catherine, a mysterious classmate of Licca, initially possesses the Calling Choker and anonymously summons Doll Izumi to shield Licca from threats. After Misty captures Catherine and the choker is lost, Licca's best friend Sumire Shinohara discovers the artifact, becoming Doll Izumi's new summoner.

In battle, Doll Izumi wields her signature baton weapon, the "Light Circle," launching it in precise, boomerang-like throws for ranged attacks. Her combat style emphasizes agility and precision, though specific techniques or detailed battle contributions receive less documentation than those of her fellow knights.

Available sources consistently portray Doll Izumi as fiercely loyal to the Doll Kingdom's royal family. However, they focus primarily on her core protective function, offering minimal exploration of her backstory, personal motivations, internal conflicts, or evolution beyond this role.