Jonathan "Johnny" Klondike operates as a knick-knack salesman, first from a booth near Clover Tower and later a permanent neighborhood shop. He provides Maya, Rachel, and Clara with the Glitter Charms enabling their transformations. His appearance features blonde hair often under a blue beach hat, a white shirt with red shoulder accents, light brown pants, brown shoes, and while working, a pink apron with heart-shaped pockets.

His true identity is Jonathan Klondike, a royal knight from Splendorius (originally Trump Kingdom). He journeyed to Earth seeking his fiancée, Princess Marie Ange (Marie Angelica), after the Mercenares (Jikochuu) devastated their kingdom. During this search, he discovered an egg by a river that hatched into a baby named Ai (Dina), whom he became the primary, protective, and kind caretaker for.

Initially evasive about his magical knowledge, he eventually reveals his knightly past. As Sir Jonathan, he dons silver armor and wields a sword capable of countering dark energy. He intervenes critically in battles, shielding the Cures from attacks and instructing them during confrontations with villains like Bel and Regina. His central relationship is with Marie Ange, recalling shared moments like train rides and archery before her kingdom's fall. He witnesses her psyche split into Regina and Aguri, and later her fade away, though he briefly encounters her spirit afterward.

Following the kingdom's transition to a republic, he becomes its first president. One year after the main conflict, an impostor (Kurata) nearly incites an international crisis by framing him, but the Cures and Regina expose the deception, reinstating his leadership. His personality blends approachability with cryptic guidance, often avoiding direct answers to encourage others to find solutions independently. He maintains trusting relationships with the core team, entrusting them with Ai's safety and the kingdom's defense.