"Deltora Quest" is a manga adaptation of the fantasy novel series by Emily Rodda, illustrated by Makoto Niwano. The story is set in the fictional land of Deltora, a kingdom once protected by the magical Belt of Deltora, which is embedded with seven gemstones. Each gemstone grants a unique power and represents one of Deltora's seven tribes. The kingdom falls into chaos when the Belt is stolen and the gemstones are scattered, allowing the Shadow Lord, an evil sorcerer, to invade and enslave the land.

The protagonist, Lief, is a young blacksmith's son who discovers his destiny to restore the Belt of Deltora. Guided by his father's journal, Lief embarks on a perilous journey to retrieve the seven gemstones. He is joined by Barda, a former palace guard and Lief's protector, and Jasmine, a fierce and resourceful forest girl with a loyal pet wildcat named Filli. Together, the trio travels across Deltora, facing treacherous landscapes, monstrous creatures, and the Shadow Lord's minions.

Each gemstone is hidden in a different region of Deltora, guarded by unique challenges tied to the traits of the tribes that once protected them. The group encounters riddles, traps, and moral dilemmas, testing their courage, intelligence, and unity. Along the way, they uncover the history of Deltora, the origins of the Shadow Lord, and the significance of the Belt in maintaining the kingdom's balance.

As the quest progresses, Lief grows from an inexperienced youth into a determined leader, while Barda and Jasmine reveal their own strengths and vulnerabilities. The Shadow Lord's influence looms over their journey, with his agents constantly pursuing them. The final confrontation reveals the true nature of the Belt and the sacrifices required to defeat the Shadow Lord and restore peace to Deltora.

The manga faithfully adapts the novel's episodic structure, with each arc focusing on the retrieval of a specific gemstone. The narrative emphasizes themes of friendship, perseverance, and the struggle against tyranny, while maintaining a sense of adventure and mystery. The characters' development and the world-building contribute to a cohesive and engaging fantasy tale.