Murumo, a mischievous 8 cm-tall fairy and younger brother of Mirmo, partners with Kyle Matsutake, a wealthy human, wielding a snare drum as his magical instrument. His striking appearance features pink hair, vibrant blue attire, a red bow tie, and a hat topped with twin antenna-like protrusions that crackle with lightning when angered—unleashing attacks dubbed “Electric Beam!” or “Mulu Electrifying Light!”

Driven by an insatiable craving for marshmallows, Murumo devises playful schemes to satisfy his sweet tooth, from deploying calculated cuteness to exposing secrets like Katie and Dylan’s dates to blackmail Kyle into spoiling him. Though prone to greed and selfish antics, he reveals unwavering loyalty to allies, readily aiding them in crises. His speech peppers phrases like “deshu” and “mashu,” amplifying his whimsical charm.

Murumo’s dynamic with Mirmo oscillates between sibling rivalry and reluctant teamwork, often leaning into his role as the cheeky, competitive younger brother. Across adventures with fellow fairies and humans, he navigates challenges through a blend of magnetic charisma and strategic mischief, maintaining consistency in his manga portrayals. While his core traits anchor his actions, expanded explorations of his background or evolution in spin-offs or films remain absent beyond the central series and manga narratives.