Principessa Rosa stands as the narrative's gentle yet naive heart. Confined within castle walls, she endures profound loneliness and yearns for both companionship and rescue by a prince. Her appreciation for simple beauty manifests in a particular fondness for white roses.

Her path collides with Lucifer, an ogre sorcerer wielding magic to menace the kingdom unless she consents to marry him. Despite Lucifer's promises of power and riches, she refuses his demand, displaying defiant courage against his threats. This rejection results in her kidnapping by Lucifer when his deadline passes, necessitating rescue.

Rosa's interactions reveal her core value: she prizes inner character above status or wealth. She expresses appreciation for Pierre's positive qualities even after he confesses to deceptive circumstances surrounding his identity and background, demonstrating her capacity to perceive genuine virtue beyond appearances or falsehoods.

Her rescue is achieved by Pierre and Pero during a confrontation where Lucifer transforms into a terrifying three-headed dragon; the horrific sight causes Rosa to faint from shock. Following these events, she forms a relationship with Pierre, exchanging royal solitude for a shared life. Her story culminates in marriage to Pierre, signifying her journey from isolation to companionship.