Paako, known as Perman #3, is the superhero identity of Sumire Hoshino, a famous Japanese child actress. Her double life grants freedom from the constraints of celebrity, where she maintains a polite and gentle public persona; her true self emerges during superhero activities. As Paako, she exhibits a tomboyish, brave, bold, hot-headed, and headstrong personality, often dominating interactions and quarreling with fellow Perman Mitsuo Suwa over responsibilities or his affections for others. This persona contrasts with her celebrity identity but represents her genuine self. The superhero role provides relief from the performative demands of fame. She wears the standard Perman outfit—a red helmet, green cape, and communication badge—over a distinctive pink dress during missions.

Relationships define key aspects of her character. Mitsuo Suwa (Perman #1) holds exceptional significance. Despite frequently insulting him, she consistently prioritizes his safety and well-being, demonstrating deep-seated care. She harbors romantic feelings for him, considering him her "treasure," though struggles to express this directly. Her conflicts with Michiko Sawada stem from rivalry over Mitsuo's attention, though Michiko also admires both her celebrity and superhero identities.

Character development occurs through narrative milestones. Initially, she rigorously conceals her identity from all teammates. In the series' conclusion, she reveals herself as Sumire exclusively to Mitsuo before his departure to Bird Planet, confessing her love and proposing marriage, which he accepts. This moment resolves their longstanding romantic tension. Her story extends beyond "Perman" through cameos in the "Doraemon" series. As an adult actress, she references waiting for Mitsuo's return from another planet, confirming their enduring connection and her continued secrecy about their past. Her name "Paako" originates as a teammate-given nickname meaning "Per-girl." The civilian name Sumire derives from the Japanese word for violet flower. Early character designs depicted her with blonde hair, later standardized to brown.