Sailor Cocoon was the Sailor Senshi of the planet Cocoon, which was the home world of the Sailor Animamate, Sailor Heavy Metal Papillon as well. Her Sailor Crystal-grade Star Seed was stolen by the Sailor Animamate-in-question, who wanted to win Sailor Galaxia's favor, hoping to be granted a Sailor Crystal-grade Star Seed, becoming a Senshi and ruling over a planet of her own.