Taruruto emerges from the magical realm as a self-proclaimed great wizard, summoned into the human world when fifth grader Honmaru Edojo, in extreme distress, accidentally recites the "Hontou ni Komatanga" spell from the Great Magic Encyclopedia. This act forges an unbreakable connection, binding Taruruto as Honmaru's constant companion. He magically transforms a drawer in Honmaru's desk into his personal living space.

Resembling a young child, Taruruto sports spiky brown hair hidden beneath his helmet. His oversized tongue serves as a distinctive tool for both combat and interaction, especially with takoyaki. His varied magic is fundamentally unreliable, often backfiring, producing unintended effects, or expiring precisely after ten minutes. His primary magical tool, the wand "Sword Pen Magic-kun," animates objects by drawing faces on them, enabling him to wield them. He can alter his size, becoming gigantic, minuscule, or enlarging specific body parts like his face or tongue.

Taruruto exhibits overwhelming cheerfulness, innocence, and a childlike demeanor. He forms attachments quickly, displaying an all-loving, trusting nature that sometimes leaves him susceptible to manipulation. He possesses an obsessive love for takoyaki, particularly Matsugoro Naniwa's. The sight or promise of takoyaki instantly distracts him, a weakness often exploited to hinder his assistance. Verbal tics punctuate his speech, frequently exclaiming "Ahh!" when excited and repeating variations of his name reflecting his emotional state.

Despite his proclaimed status, Taruruto's inconsistent magical skills reflect his role as a wizard-in-training. Spells include "Sukerururu~" for temporary invincibility, "Mi~Mo~Ra~" summoning Mimora to attack, and "Matsuputatsu!!" splitting enemies in two, though their effectiveness varies. He possesses surprising physical strength for his size, demonstrated when pummelling the larger bully Jabao Jaba or defeating adversaries like Asuka with a single punch. This strength and magical potential make him a pint-sized powerhouse, though focus and control remain issues.

His relationship with Honmaru evolves into deep, mutually dependent friendship. Initially summoned to solve problems, Taruruto comes to view Honmaru as his best friend. He becomes fiercely protective, showing rare anger when Honmaru is insulted or endangered. Separation causes him significant distress. His magical presence starts as a secret, but circumstances, notably a critical martial arts tournament where he represents Honmaru's class against Nezo Zakenja, force his abilities into the open. Desperation leads him to reveal his magic publicly, though the immediate crisis prevents classmates from dwelling on it.

Connections extend beyond Honmaru. He develops a surrogate family bond with Honmaru's mother, Chizuru, who affectionately calls him "Taru-chan" and sees a younger Honmaru in him. He shares a complex dynamic with Mimora, a fellow young wizard utterly infatuated with him, whom he addresses formally as "Taru-sama." The dark wizard Rivar views him as a rival, seeking his elimination to gain Mimora's attention. His older sister, Ria Kinakamo, eventually arrives seeking him but decides to stay.

His story concludes following Honmaru's elementary school graduation and desire for independence. Honmaru actively de-summons Taruruto, severing their magical link and sending him back to his realm, signifying Honmaru's maturity and ending Taruruto's physical presence.