Melory is a Cocotama, a small god born from the cherished keys of a piano played by a human during childhood. Her full formal designation is "Melo Melo-Rin Hime-no-Mikoto" or "Mellow Melorin Princess-no-Mikoto". As the main female character within the franchise, she holds the title of "The Piano God".

She possesses a bright and cheerful personality, though she can become easily upset and occasionally acts naive. Melory frequently expresses her emotions through singing; her heavenly voice radiates feelings that enhance or amplify the emotions of others. She often ends sentences with "nano", conveying assertion or questioning.

Visually, Melory resembles a poodle or bunny hybrid. Her light pink fur features creamy white markings on her paws and face. She has long, floppy ears ending in tufted fur, a distinctive forehead curl, and a tail shaped like a musical note. She wears eggshell-colored underpants marked with a dark pink heart symbol, consistent with apprentice Cocotamas, and sports a dark pink bow on her head.

Melory can perform magic, activated by a specific chant. Her magic sometimes combines with other Cocotamas' powers for greater effects. She resides alongside other Cocotamas, participating in group activities and challenges.