Mary Bell, an ancient floral magician from the Flower Magic World, defies her preschool-like appearance with over half a million years of existence. Tasked with guiding humans through flower-based enchantments, she wields a mystical tambourine and partners with Tambourine, a steadfast ally from the Seelie Court. Her magic blends inherited incantations—"Paparin, Berlin, Lan Lan Run" from her composed magician father and "Mamarin, Berlin, Lunrunlun" from her mother, the wandering "Fairy Sweet Maker" who crafts dream-inspiring confections.

When siblings Yuuri and Ken summon her to revive their family’s failing flower shop, Mary Bell embeds herself in Sunny Bell’s coastal community. Her journey crescendos as she challenges the Holy Tree’s edict to strip Earth of its flora, leveraging humanity’s collective empathy to overturn the decree. This victory anchors her indefinite stay on Earth, where she perpetuates her mission of hope.

In *Phoenix no Kagi*, she intervenes in the phoenix Toto’s corrupted rebirth ritual, sparked by a tainted key. Rallying allies across realms, she hunts for a pure soul-linked key to reverse Toto’s descent into darkness, reaffirming her role as a bridge between magical and human spheres.

Eternally buoyant and resolute, Mary Bell champions her motto—"Just leave it to Mary Bell!"—while harmonizing her magic with musical flourishes, from operatic dialogues to rhythmic spells. Though distinct from fairykind, her bonds with them endure, and her ventures extend into educational realms, where she tackles everyday human challenges without straying from her central purpose.