Eric is an ordinary ten-year-old boy who accidentally discovers a glowing, rainbow-colored staircase hidden inside a small basement closet. Although initially hesitant to explore the strange environment at the bottom of the stairs, he quickly steps up as a leader when he and his friends face an unexpected monster attack. He takes his promises seriously and feels a strong moral obligation to help those in trouble, even when it puts his own safety at risk.

Neal lives at the end of Eric's street and is his best friend. He has a tendency to be lazy, accidentally kicking a soccer ball into a hidden closet rather than helping organize the basement clutter. Despite his frequent complaints about dark places and his initial reluctance to follow the mysterious staircase, he stays fiercely loyal to his friends and provides comic relief during stressful situations.

Julie is a cheerful, confident ten-year-old girl who has been friends with Eric and Neal since kindergarten. She is highly responsible and pragmatic, actively helping Eric clean his basement while Neal goofs off. Her curiosity and decisive actions—such as shutting the closet door to test a theory—directly cause the group to discover the hidden world of Droon.

Keeah is the young princess of Droon, recognizable by her pale skin, green eyes, and long blue tunic. She is actively hunted by an evil sorcerer but remains fiercely determined to protect her father's kingdom. Though she is still learning her magic, she possesses potent healing abilities and a sharp, practical mind that allows her to strike quick alliances.

Lord Sparr is an evil, powerful sorcerer trying to conquer Droon. While he looks mostly human and wears a long black coat, he has distinctive purple fins behind his ears that darken when he is furious. He uses strange red creatures called Ninns to execute his cruel orders and actively hunts down anyone who opposes his quest to obtain magical artifacts.

Galen is the five-hundred-year-old first wizard of Droon. He dresses in traditional blue robes with a matching hat and sports a long white beard. He is highly knowledgeable about the magical and political state of his world, though his advanced age means his incredible powers are slowly beginning to weaken, causing the boundaries between worlds to slip.

Max is a giant spider-troll who serves as the guardian of Galen Longbeard's tower. He possesses the body of a large spider attached to a humanoid troll head with orange hair, a snub nose, and a surprisingly squeaky voice. He relies on his physical strength, web-spinning skills, and absolute loyalty to assist his master's allies.

King Zello is the current ruler of Droon, leading the forces of good against an evil sorcerer's armies. He commands troops from Jaffa City and relies heavily on the magical assistance of his allies to keep his territory safe from constant attacks.

Queen Relna is the missing queen of Droon. She vanished following a major battle with evil forces at a fortress called Plud, leaving behind only a magical leather pouch that she gifted to her young daughter.

Leep is a pilka, a six-legged creature resembling a camel with long white hair. She serves as a reliable mount for traveling across Droon but has a timid nature and easily frightens at loud, unfamiliar noises.