Jibaku-kun: TWELVE WORLD STORY

In the Twelve-World, a mysterious land in an unknown dimension, humans, monsters, and spirits live together in harmony, protected by the Princess of the Needle Tower in the Zero World. When the balance is suddenly disrupted and the princess falls into a deep sleep, the monsters break free and begin attacking humans. The Great Children, troubleshooters who handle monster-related incidents, are the only ones who can restore balance. Spaak, the most skilled among them, learns of an invasion in the Zero World and meets Bucky, a young and ambitious boy who dreams of becoming the strongest. Spaak senses potential in Bucky and selects him as his successor. Bucky begins his journey to become the greatest Great Child, traveling with Kai, Pinky, and others toward the Needle Tower. Along the way, he discovers that an unknown force from another dimension is controlling the monsters.