Chop, known as UMA (Unidentified Mysterious Animal), originates from a Star Drop, celestial debris scattered after a planet's destruction. It first emerges as a small, glowing, non-verbal entity from within Lala's gummy case on Earth. Exposure to Hikaru's Miracle Light and descriptions of Okinawa triggers its evolution, granting it an antenna and a distinct body capable of teleportation.

UMA communicates primarily through emotional resonance and music, especially "The Shooting Star Song," which soothes it and forges connections. The creature instinctively teleports in reaction to intense emotions like fear or excitement, accidentally transporting Hikaru, Lala, and Fuwa to locations worldwide, including the Nazca Lines, Angel Falls, and the North Pole. A music box becomes a cherished possession, symbolizing its deepening attachments.

Designated "the most precious treasure in the universe," UMA becomes a target for alien hunters seeking its power. Capture and separation from Lala cause extreme distress, triggering uncontrolled growth that endangers Earth. Stability is only achieved when the Pretty Cures unite to sing "Twinkle Stars," channeling shared resolve and empathy. This intervention allows UMA to reach its final form: a fully formed celestial body.

The story concludes with UMA departing as a new planet, carrying the music box as a memento before journeying into deep space. Its path illustrates a transformation from a vulnerable, instinct-driven entity into a conscious being of cosmic significance, facilitated by bonds forged through protection and shared song.