Harry, a hamster-form entity, sports orange and cream fur with a crimson-tufted mane, brown eyes accentuated by scarlet lashes, and a gold chain necklace that suppresses his monstrous alter ego. A lone pearl earring pierces his left ear. Hailing from the Harihari Clan in a dystopian future, he allied with comrades Listol and Bicine under Criasu Corporation’s false promise to cure their plague-ravaged community, only to witness their home’s annihilation. Betrayed, he rescued Cure Tomorrow—Hugtan’s matured counterpart—from Criasu, fleeing through time to regress her into infancy.

Acting as Hugtan’s guardian and tactical advisor to the Cures, he balances bravado with hypersensitivity toward mistaken mouse comparisons. Though prone to touting his human form’s charm, his loyalty to allies—especially Hugtan—remains unwavering. Homare Kagayaki’s unrequited affections prompt gentle but firm rejection, preserving their camaraderie. Fractured ties with Bicine and Listol, once loyal to Criasu, mend after their redemption, though past clashes linger.

Removing his chain unleashes a hulking monstrous state: fur blackened, claws and fangs bared. Initially feral, this form is pacified by Cure Tomorrow and Cure Étoile, later mastered as a tactical asset against Criasu. Combat skills span agile rodent maneuvers and humanoid prowess, augmented by barrier conjuring and chain-forging to reseal transformations.

In *Miracle Universe*, he joins cross-dimensional Cure teams in cosmic warfare, blending levity—like evading Ruru’s icy hugs—with tactical ingenuity, hijacking vehicles or shielding allies mid-battle.

Post-conflict, he accompanies Hugtan to a restored future, coexisting with former foes. His human self shares silent moments with Cure Tomorrow, witnessing pivotal events such as Hugtan’s rebirth in a healed timeline.