Jill is a young princess in the kingdom of Märchen who struggles with deep insecurities regarding her appearance. She sits by her beautiful, vain mother every day, hoping to win her attention and approval. When a disastrous parade publicly humiliates her, she flees the palace. She joins her cousin on a dangerous quest for the Seeing Glass, believing the magical artifact will finally grant her the beauty she desperately wants.

Jack is Jill's cousin, a young boy living on the outskirts of Märchen who lacks self-esteem. Constantly belittled by his father and teased by the village boys, he searches externally for respect and admiration. After making a terrible trade at the market to impress his peers, he joins Jill on a dangerous quest to find the Seeing Glass, hoping it will make him popular.

The Frog is an amphibian living in the kingdom of Märchen. He gains the unusual ability to speak when the stars grant his wish to be understood by a beautiful human. He serves as a vocal companion for Jack and Jill during their travels. He frequently warns the children of impending danger, though his advice sometimes stems from simple fear rather than true wisdom.

The Narrator is an unseen storyteller who breaks the fourth wall to speak directly to the reader. He interrupts the narrative to provide context, offer warnings about frightening events, and encourage independent thinking. His active presence mimics the oral tradition of old fairy tales.

The Old Woman is a mysterious magical figure who intercepts Jack and Jill. She knows exactly what the children want and promises Jack popularity and Jill beauty if they find the lost Seeing Glass. She binds the children to a deadly oath and enchants Jack's single bean to grow into a giant beanstalk to start their journey.

The Clothier is a charismatic traveling merchant who preys on the vanity of the royal court of Märchen. He claims his special silk is invisible to anyone without the finest eyes. This psychological trick convinces the insecure royals to pretend they see the fabric, leading directly to Jill's public humiliation.

The Salesman is a fast-talking swindler who targets vulnerable people on the road. He stops Jack and offers a single magic bean in exchange for the family cow. He uses the peer pressure of the local village boys to convince Jack to make the terrible trade.

Jill's mother is the queen of Märchen. She is obsessed with her physical appearance and expects absolute perfection from her surroundings. She frequently ignores or criticizes her daughter, creating a toxic environment that drives Jill away from the palace.

Jack's father is a villager who expects his son to act like a grown man. He frequently belittles Jack, contributing heavily to the boy's severe lack of self-esteem. He reacts with intense rage when Jack returns from the market with a poor trade.

Eddie is a massive, fire-breathing giant salamander who lives deep beneath the Goblin Kingdom. Though he is feared as a terrible beast by the goblins above him, he is actually quite lonely and speaks the same amphibian language as the frog.

The Three Ravens are talking birds who represent the past, present, and future. They appear during the journey to offer cryptic wisdom and guidance, suggesting that the children are looking for the wrong thing entirely in their quest for the mirror.

The Fisherman is a grieving man in a seaside village who lost his daughter to a mermaid. He remains vigilant along the water, determined to protect others from falling victim to the same trap.

Originally a starving man outside the palace, the beggar later becomes a judge. After he kindly gives his blanket to the humiliated princess during the parade, the king rewards him with a judicial position to ensure he never has to beg again.

The Mermaid is a magical sea creature who sings a beautiful song promising a life without tears. She speaks with Jill through the night, presenting herself as a victim of the village fishermen. She uses her apparent vulnerability to lure insecure humans into the ocean.

The Goblin Leader commands a vast underground kingdom filled with magical temptations. He and his subjects capture travelers and offer them exactly what they want to hear. He operates a dangerous marriage test for his human captives.