"Magical Taruruuto-kun" centers around Taruruuto, a mischievous and clumsy young demon from the Demon World who is sent to the Human World to complete his training. His mission is to cause chaos and mischief, but his lack of skill often leads to unintended consequences. Taruruuto is accompanied by his loyal but equally inept assistant, Donperignon, a small, bird-like creature who frequently finds himself caught up in Taruruuto's schemes.

The story primarily revolves around Taruruuto's interactions with a human boy named Takashi Shinguji, who becomes his unwilling partner. Takashi is an ordinary elementary school student who stumbles upon Taruruuto's magical abilities and is reluctantly drawn into his chaotic adventures. Despite his initial reluctance, Takashi often ends up helping Taruruuto navigate the challenges of the Human World, though their efforts are frequently undermined by Taruruuto's incompetence and overconfidence.

Throughout the series, Taruruuto attempts to prove his worth as a demon by causing trouble, but his plans often backfire, leading to humorous and unpredictable outcomes. The narrative is episodic, with each episode presenting a new scenario where Taruruuto tries to outwit humans, rival demons, or even his own superiors in the Demon World. Despite his failures, Taruruuto's persistence and occasional flashes of cleverness keep the story engaging.

Key recurring characters include Taruruuto's rival, the more skilled and arrogant demon Akuma-kun, who often competes with Taruruuto to prove his superiority. Additionally, Takashi's classmates and family members occasionally become involved in Taruruuto's antics, adding to the comedic and chaotic nature of the series. The dynamic between Taruruuto and Takashi evolves over time, with moments of camaraderie and mutual understanding emerging amidst the constant chaos.

The series blends slapstick comedy, magical elements, and lighthearted mischief, creating a whimsical and entertaining narrative. While Taruruuto's primary goal is to cause trouble, his interactions with the human world often lead to unexpected lessons about friendship, perseverance, and the consequences of one's actions. The episodic structure allows for a variety of humorous and imaginative scenarios, making "Magical Taruruuto-kun" a light-hearted and enjoyable series.