Sailor Moon Crystal-Lost Star

Aki woke up one day, bound for school. On the way, she finds a yellow cat with a star on it's head. That's when she discovers that she's a Sailor Senshi, Sailor Celeste. The cat, Hoshi explains to her that no one knows how she became a Senshi. She winds up moving to Tokyo and she meets another Sailor Senshi, Usagi who she forms a powerful friendship with. Eventually they find the rest of the Senshis and learn of her real identity, Princess Serenity's younger sister, Hotaru. She discovers that in her past life, she was stolen from the Moon Kingdom and that her life is known as the Lost Star.