Crystal is a girl, which birthday place is unknown. She makes her first apperance in Sailor Moon X, the sixst season.
One day, she appears in the near of Usagi. Luna sees her, but she thinks Crystal would be a normal girl. Crystal continues to walk, and sees a demon. The demon saw Crystal too and beginned to attack her. Then appeared the Sailor Scouts. While they fighted against the demons, Sailor Uranus comes and brings Crystal in Safety.. When the Sailor Senshi have been caught, and did not come free, Crystal appeared already and pelted with stones the demons. The demon ran after Crystal, but she was fast. She went into a dead end and behind her was the demon. But suddenly, a glowing came from Crystal and then she had received two bracelets, and she could not take off them. A sound wave came from Crystals hand and pushed the demon away, and freed the Sailor Scouts. Then Crystal fled. Sailor Moon defeated the demon with her new moon scepter. Later, Usagi and Ami searched for Crystal, and found her in the park. When she wanted to know why she had suddenly get this power. Crystal could not answer. Luna came, and says, that Crystal is maybe a new ally.